Gifford Garden Archives, July 2000 - June 2001

Gifford Garden Archives, July 2001 - January 2003

Week of 19 July 1999

Native to the eastern United States, coneflowers, Echinacea sp., are members of the composite family, Asteraceae. The composite family is one of nature’s largest, containing 950 genera and over 20,000 species. Coneflowers are closely allied with sunflowers, the helianthus tribe. The purple coneflower, E. purpurea, is at its peak in the garden. We use several cultivars bred for their vivid profuse flowers. Echinacea purpurea ‘Bright Star’ and ‘Magnus’ have especially rosy pink rays with maroon disks. Echinacea purpurea ‘White Swan’ is the white flowering cultivar in the garden. All coneflowers are easy to grow, require practically no maintenance, are excellent for cutting, and attract butterflies. Truly a low maintenance perennial, Echinacea is making a resurgence not only in today’s garden, but also in drug and nutrition centers for its reported benefit in bolstering the immune system.

Another native to eastern North America are the beebalms, Monarda sp., members of the mint family, Lamiaceae. The perennial garden has several cultivars of M. didyma, beebalm or Oswego tea. M. didyma ‘Adam’ is rose red, ‘Croftway Pink’, obviously pink. An unusual native beebalm is M. punctata, the dotted mint. The whorls of purple spotted yellow flowers are ringed with large showy, pink bracts. It’s questionable as to whether beebalms should be on the "low maintenance perennial" list as they can be susceptible to powdery mildew and are somewhat invasive.

A few tips on controlling powdery mildew … First is proper siting of the plant. Chose a garden location with plenty of air circulation to discourage the settling of the fungal spores on the leaf surface. Also, thinning of the beebalm stand by 1/3 or more when the stems are about a foot high will facilitate air movement through the plant. Finally, while beebalms will thrive in dry soils, we plant our monardas with organic soil amendments to retain moisture. This seems to aid the plant in warding off powdery mildew infestations. Beebalms are one of the best hummingbird attracting plants.

The butterfly weed is one of about 2,000 species of the milkweed family, Asclepiadaceae. This handsome native, Asclepias tuberosa, is in flower in the "sun beds’ by the octagonal sunken garden. Look for those brilliant orange patches of color in upland fields throughout our area. The plant is commonly found in association with our native upland grasses, little bluestem. This plant prefers open, sunny locations and dry gravelly soil; do not use soil amendments or fertilize this plant. It is one of the most drought-tolerant plants in the garden and makes the low maintenance list. We also have other representatives of the genus in the perennial garden: A. incarnata ‘Ice Ballet’, a cultivar of the swamp milkweed with its small tight umbels of white flowers. A. verticillata, the horsetail milkweed, is white with purple clustered flowers. Visitors will note the colony of common milkweed, A. syriaca, near the entrance of the garden. While not particularly showy, this plant is crucial in the success of the monarch butterfly. The female monarch selects this plant exclusively for egg laying. We often observe the egg mass and chrysalis on these plants.

To avoid further botanical ramblings, I’ll cover the perennial garden’s well represented sunflowers next week.

Brad Roeller
Manager of the IES Display Gardens

Week of 26 July 1999

Sunflowers, Helianthus sp., are widely represented throughout the perennial garden. Largely native to North America, they exist as both true annuals and perennials. The annual sunflowers are widely used for their edible seeds and oil, while both annual and perennial sunflowers are used for their mid-summer ornamental garden value.

Two of the showier sunflowers in the perennial garden are actually native to New York state. H. decapetalus, the thin-leaf sunflower, can be found in the hummingbird bed. Heliopsis helianthioides, very closely related to the sunflowers and taxonomically in the same tribe, is our native oxeye and is flowering in the "sun beds" between the sunken octagonal garden and the water garden. Perhaps the most striking sunflowers in bloom this week are not sunflowers (Helianthus) at all, but the coneflowers, Rudbeckia sp. and Ratibida sp. Like Heliopsis, they exist within the same tribe as sunflowers. Rudbeckia nitida ‘Herbstone’ is the striking coneflower used throughout the perennial garden. It is the 4'+ clear yellow coneflower you encounter as you exit the terrace steps and enter the perennial garden. This low maintenance perennial will reach 7' in height in good growing years without requiring staking! Ratibida pinnata, the prairie coneflower and Rudbeckia subtomentosa, are likewise striking in size and flower making a strong statement in the xeriscape bed. Finally, the ever popular Rudbeckia fulgida var. sullivantii ‘Goldsturm’ is used throughout the IES perennial garden. All of the coneflowers native to the eastern and central United States show excellent drought tolerance, and are long flowering.

Brad Roeller
Manager of the IES Display Gardens

Week of 2 August 1999

I'm going to depart from the usual "what's hot in the garden this week" format as many of the same mid-summer bloomers are doing, and will continue to do, "their thing" again this week. (However, do visit our water garden as the waterlilies are starting to gear-up for a good flowering.)

For the last month I've frequently been asked how I keep the perennial garden looking so well with the meager rainfall. First of all, kudos go to the dedicated IES gardeners, Margaret, Colleen, and Laura! Their hard work this past spring has paid dividends this summer in-so-far-as preparing the plants for this nasty drought. Here are a few tips to keep your garden and lawn alive and hopefully beautiful in these types of summers:

• Mulch, mulch, mulch! We apply 2" of spruce bark mulch to all garden beds in May-June-before the heat of the summer and lack of rainfall stresses the plants. This task is done in association with spring garden cleanup where we cultivate the beds, check and adjust the pH if necessary, and apply a slow release totally organic fertilizer. We try to time this operation immediately after a thorough soaking from a spring rain. It's amazing how long the mulch will retain this soil moisture. If you have mulched, it's not to late, just time your mulching to a rainfall (wishful thinking) or water your plants thoroughly before you mulch.
• Select and grow drought tolerant plants that are properly sited (sun versus shade) in your landscape. Be generous with organic soil amendments, which will retain moisture, when planting
• If you are not on a water restriction, water only those plants that show signs of drought stress (i.e. "flagging" foliage). Deep water the root zone. Do not "spritz" water over the surface as this will encourage the roots to actually grow up towards the surface and be subject to higher temperatures and lack of moisture further stressing the plants. (Note that even the best of the drought tolerant plants may "flag" in the heat of the day in direct sunlight. Assess the condition of your plants early in the morning or when shaded for several hours.)
• Brown, dried-up lawns are not dead. Most northern lawn grasses are cool weather plants not well adapted to high temperatures and drought. Our lawns naturally go senescent or are "resting" during summers like these. The tops (i.e. leaf blades) are dead, but the roots are alive and just waiting for rain and cooler nighttime temperatures to initiate new growth. DO NOT feed your lawn this summer thinking to help it. If you do feed, you must irrigate it regularly with at least an inch of water per week. Do not mow your lawns, even to cut off the drought tolerant weeds like chickory and bird's foot trefoil. Importantly, stay off your lawns as much as possible. Even foot traffic can damage the growing tips of the grass and severely impact the plant.
• The use of organic biostimulants (i.e. sea kelp extracts, humic acid extracts, nitrogen fixing and phosphorus solubilizing bacteria, proteins, amino acids...) may be helpful in the recovery of drought stresses plants. More on biostimulants in a later "highlights".
• Keep the faith! Mother nature has a way of taking care of us. I wouldn't be surprised if we have abundant snowfall this winter!

Brad Roeller
Manager of the IES Display Gardens

Week of 9 August 1999

So many blooming plants to choose from and so little space! What a wonderful dilemma. I'll limit myself to highlight another wonderful native becoming quite popular in U.S. gardens, the Eupatoriums, commonly called bonesets or thoroughworts.

Long before North American native Eupatoriums became popular in our American gardens, the English were importing them for their perennial borders. Here at the IES perennial garden where we are actively evaluating and incorporating natives into our borders, we quickly realized the potential of several indigenous Eupatoriums.

We have selected four Eupatoriums and one close relative, Vernonia noveboracensis, New York ironweed, for incorporation into various areas of the perennial garden.

Eupatorium perfoliatum, boneset, is the white thoroughwort with the unmistakable wrinkled leaves that unite basally around the stem (perfoliate, hence the specific name, perfoliatum). It is a great garden plant that sometimes comes in the less common purple form. Although like most Eupatoriums which are found in low lying moist thickets and wet meadows, the do fine in ordinary garden soil amended with organic matter. E. perfoliatum can be found in our "arbor beds" as you exit the terrace steps and enter the garden.

E. rugosum, white snakeroot, is another white Eupatorium with heart-shaped leaves on slender petioles. The brilliant white 1/4" flower heads are grouped into flat-topped corymbs. This is a very useful perennial for its long lasting blooms flowering at a time when white blooming plants are not common in the garden. Note that white snakeroot is poisonous to cows and milk from cows that have ingested the plant is toxic to humans. Additionally, this Eupatorium will tolerate quite a bit of shade — an added plus for gardeners. Finally, for those of you who want to be taxonomically correct, the botanic name has recently been changed to Ageratina altissima. You can find white snakeroot in the poisonous plant bed.

In our xeriscape bed we are evaluating a Joe-pye-weed, E.purpureum, the sweet Joe-pye-weed, for its drought tolerance as well as its flowering ability. The native Joe-pye-weeds — E. maculatum, spotted Joe-pye-weed; E.fistulosum, hollow Joe-pye-weed; and E. purpureum, the sweet Joe-pye-weed — are all indigenous to New York and can be found in most low lying wet meadows. They are very effective for naturalizing in the garden and, surprisingly, show good drought tolerance.

Eupatorium coelestinum, mist flower or hardy ageratum, is the only bluish Eupatorium and is related to the common ageratum grown as an annual. It is native to south and central United States. All Eupatoriums are excellent for attracting butterflies and we have chosen the mist flower for our butterfly garden.

New York ironweed, Vernonia noveboracensis, is the striking Eupatorium relative in the sun beds. While they suggest Joe-pie-weeds, the plant has more open flower clusters, are deeper in color (toward violet) and have more slender, sessile, alternative leaves. Even in this record- setting drought year the ironweeds are well over 6' in height and flowering profusely!

Eupatoriums will be prominently represented in next year's new native plant bed.

Brad Roeller
Manager of the IES Display Gardens

Week of 16 August 1999

This week I’ll profile two subshrubs that are true stalwarts of our perennial garden: Russian sage and the butterfly bush.

Subshrubs are a class of garden plants that have stems that are partially woody and partially herbaceous. Other examples of popular garden plants that are subshrubs are lavender, tree peonies, and many of the Clematis. In our growing zone, subshrubs usually require severe cutting back of the previous season’s growth to guarantee survival and enhance their growing performance. (Please note that you should NOT cut back tree peonies as they typically have no difficulty initiating growth from ‘old’ wood.)

Russian sage, Perovskia atriplicifolia, is a member of the mint family, Labiatae. You can always identify plants in the mint family by their tell-tale square stems. A native of West Pakistan, this graceful aromatic subshrub is clothed in silvery gray hairs throughout the plant. Prominent one-foot tall panicles of small, whorled lavender-blue flowers grace the plant from late July through early September. Russian sage is not particular about its growing requirements other than it needs full sun and excellent drainage. It will not survive being planted in low areas where winter snow and ice accumulate. It is imperative to cut this plant back in early spring (April). Start your pruning high on the plant and continue downwards until you find ‘green’ wood. Depending on the severity of the winter and the amount of snowcover, you may have to cut back the plant to within a few inches of the ground. Some years you might be able to keep a foot or two of the present season’s ‘wood’. The more of the old growth you are able to keep, generally the larger the plant will be. Russian sages will make the IES "Top 100 Garden Plants" list as they are extremely drought tolerant, do not require any fertilization, don’t require staking, are insect and disease resistant, and, with the exception of the necessary spring pruning, are winter hardy.

The butterfly bush, Buddleia davidii, also called summer lilac, is a member of an obscure (at least to me) plant family, Loganiaceae. This is a small family of plants represented by 32 genera of almost 800 species of herbs, shrubs and trees native to the warm and tropical regions of North and South America. Buddleias, one of the larger genera of this family, are quite unusual as some species have been used as a fish poison in the tropics, some for medicinal purposes, and a number, like B. davidii and B. alternifolia, for ornamental purposes.

Buddleias prefer full sun and well-drained organic soils. As with Russian sage, buddleias must be pruned back to viable wood in early spring. We display several varieties of buddleias in our garden, including ‘black knight’, ‘royal red’, ‘white profusion’, and ‘pink chimes’. A relatively new variety of buddleias has hit the garden centers in the last few years, B.d. var. nanhoensis. This Chinese variety is somewhat smaller than its ‘cousins’, and has different foliage with a bluish cast to it. You can recognize these plants by their trade names, ‘nanho blue’, ‘nanho purple’, etc. Butterfly bushes are one of our favorite garden plants, prominently displayed throughout the garden. And, as the name suggests, with their fragrance and vivid colors they do indeed attract butterflies.

Brad Roeller
Manager of the IES Display Gardens

Week of 23 August 1999

This is the time of the growing season that roses start to pique my interest. All summer long the roses have not lived up to the standards of flowering that they attained in June. However, with the recent rainfall coupled with the hint of cooler nights, roses are enjoying similar growing conditions that they experienced in June. Visitors to the Shankman Rose Garden will notice the proliferation of new growth and flower buds. The late summer-early fall flush of bloom is at hand, with peak flowering about a week or two away.

Be sure to stop by the Shankman Rose Garden and pick up one of the brochures in the lucite box located in the center bed. In the brochure you will find the 1998 Year-End Report highlighting both the roses in the garden and the success of the season’s maintenance. The comparison and evaluation of growing roses both in a traditional way (i.e., high chemical fertilization and dependence upon chemical pesticides) and the organic way (i.e., low nitrogen insoluble, organic fertilizers and botanical pesticides as needed) have been eye opening. After several years of trial and error, especially in the relatively new field of organic pest control measures, I am able to say that you can indeed grow roses employing a totally organic growing regime as well if not better than using the "traditional" approach. You will be able to find a detailed list of the seasonal treatments for both the "chemical" beds and the "organic" beds in an insert in the brochure.

Highlighting a few of the roses that I like in the garden:

• I’m generally not enamored with hybrid tea roses due to the constant care and lack of assured winter hardiness, but Jardin de Bagatelle is one of the best I’ve ever grown. It is an extremely vigorous grower with thick, strong canes and excellent dark foliage. The rose is white with subtle pink tinges around the margins of the petals, and is one of the most fragrant I’ve ever smelled. Best of all, it is the most winter hardy hybrid tea I’ve found.
• I’m becoming a big fan of shrub roses, especially the relatively new "English" roses developed by David Austin. It took Mr. Austin over 20 years of rose breeding to successfully cross a variety of old shrub and species roses with the "modern" floribunda roses to insure reblooming. There are numerous excellent "Austin" or "English" roses; two of my favorites are Othello and Heritage. "Graham Thomas" is another great English rose.

Brad Roeller
Manager of the IES Display Gardens

Week of 30 August 1999

This week I’m going to talk about anemones. The venerable former Director of Horticulture at The New York Botanical Garden described anemones in his definitive Encyclopedia of Horticulture as "Charming perennial flowering plants suitable for the herbaceous border, rock garden, and for naturalizing in open spaces among leaf-losing trees." Some are suitable for greenhouse cultivation. Here in the Hudson Valley growing anemones for cut flowers was an important industry around the turn of the century. There remain only a few greenhouses that still grow anemones for this purpose.

Anemones belong to the buttercup family, Ranunculaceae. The word Anemone is derived from anemos, the wind, hence the common name "windflower’. Anemones grow in Europe, Japan and North America. The plant has no petals; the showy part of the flower consists of petal-like sepals.

I have several favorite anemones. The two I’ll concentrate on this week are Anemone hupehensis, the Japanese anemone and A. x hybrida, also referred to as Japanese anemone. A. hupehensis is the species native to Japan and Central China from which all hybrid Japanese anemones are derived. The plant has just begun to show off its many rounded, rose pink sepals that will bloom from now until frost. Japanese anemones are well suited to ordinary garden soil. They are easily grown in either sun or shade, but seem to perform best in light shade. Anemone x hybrida, the hybridized form of Japanese anemone, resulted from crosses made from A. hupehensis and A. vitifolia, a Himalayan species with lighter pink flowers. The result has yielded offspring that range in color from pure white to deep pink and salmon and flowers with forms ranging from single flowers to semi-double and double. Most of the Japanese anemones you encounter in nurseries are cultivars of A.x hybrida. One of my favorites happens to be one of the oldest cultivars, "whirlwind", a white semi-double that grows 3 feet tall.

Both Japanese anemones will make the Institute’s "Top 100" list of perennials for northern gardens, as they are definitely low maintenance, essentially free from insect and disease problems, seldom need staking, and have low watering and fertilization needs. Japanese anemones are great for cutting. Of slight concern to some is the problem of invasiveness. Once established, Japanese anemones will spread from underground rootstock. I personally don’t find this a problem as the unwanted divisions have made me quite popular in the neighborhood. I like to plant Japanese anemones in the middle or back of the light shade section of the perennial border with my azaleas and rhododendrons and then leave them alone. I find the foliage quite attractive with it’s large, palmately compound basal leaves.

Look for Japanese anemones throughout the IES Perennial Garden, they’re hard to miss!

Brad Roeller
Manager of the IES Display Gardens

Week of 6 September 1999

Visitors to the IES Perennial Garden should take the time to see one of our favorite natives that started to bloom recently. Near the steps to the Gifford House patio you can’t miss seeing the colony of Culver’s root, Veronicastrum virginicum. The real beauty of the plant is the multitude of 6 to 9 inch racemes of tiny, white or sometimes pale blue flowers. What appeals to me about the flowers is the corollas.

A short botany lesson might be in order as I’m prone to talk "botanically correct". The corolla is part of the perianth. The perianth is the combined outer and inner series of a flower; the calyx and the corolla. In the case of Culver’s root, the corolla is what we call salverform (said of corollas with a slender tube expanding into a flat limb) with conspicuously exserted (projecting outward and beyond) stamens (the male reproductive organ in a flower). What all this boils down to is that Culver’s root has exquisite tall spires of tiny flowers that are a great addition to the late summer perennial border. Culver’s root is native to northeastern woodlands and meadows. Since it is a tall perennial we like to combine it with our native asters, which are just coming into bloom, and Japanese anemones which also are blooming presently in the garden. Culver’s root certainly qualifies as a low maintenance perennial: it has been trouble-free in our gardens for years. The plant will grow in ordinary garden soil amended with compost; however, if you’re lucky enough to garden in a low lying wet meadow or have a pond or stream on your property, Culver’s root will thrive. The Culver’s root I mentioned earlier growing by the Gifford House patio is actually a cultivar, V. virginicum "Albo-Roseum" with pinkish flowers.

Another plant that is worth highlighting this week is another one of our favorites, the bluebeard, Caryopteris x clandonensis. This plant is another example of a subshrub, a plant that is intermediate between a woody and herbaceous plant. The bluebeard, also known as the blue mist flower, is a result of a cross made of C. incana and C. mongholica, both native to northern China and Japan. The result of this cross, made in 1933, is an outstanding late-flowering plant of particular interest for its intense blue flowers. There are not many shrubs or subshrubs that can boast blue flowers. We display this plant in our Butterfly Garden where it’s in its glory right now. If you acquire this plant, be advised that it’s marginally hardy in our growing zone and does need protection during the dormant season. Be sure to provide 2 to 3 inches of mulch around the plant after we have had our first "killing" frost. One further precaution I perform with this plant is to add evergreen boughs formed like a "tee-pee" over top the plant once there is frost in the ground. This will protect it from the drying winds of winter. You must severely cut back this plant in early spring as you would Buddleias. With a little care you will be generously rewarded in the late summer.

Brad Roeller
Manager of the IES Display Gardens

Week of 13 September 1999

Due to preparations for the upcoming IES Fall Plant Sale happening this weekend (Saturday, 18 September and Sunday, 19 September), I’m forced to be brief with this week’s highlights.

One of my favorite, and little known, fall-blooming perennials is getting ready to bloom in the IES Perennial Garden. The plant is the toad-lily, Tricyrtis hirta, a member of the lily family, Liliaceae. Toad-lilies are native to shaded woodlands throughout the Himalayas, Japan and China. I always enjoy looking into the derivation of the botanic names of plants. In this case the name comes from treis, three, and kyrtos, convex, from the three outer petals or perianth segments which have sacs or pouches at their bases.

The most commonly used toad-lily is Tricyrtis hirta, which is the hairy toad-lily, named for the fuzzy, soft hairs that cover the plant. The plant has erect, arching stems that grow about two feet tall in our garden. It prefers light shade, but will tolerate a considerable amount of shade and still bloom. One growing tip: this plant is just beginning to start flowering and will continue to bloom right up until a killing frost; because of this, and to hasten the blooming season, I recommend planting toad-lilies in light shade. Additionally, the plant likes rich, humus soil that tends to be on the acid side. Once established, toad-lilies will form a colony as the plant has rhizomatous roots.

If the foliage and arching stems aren’t enough, the flowers are truly exceptional. One of the better descriptions of the flowers comes from the venerable horticulturists T. H. Everett: "The flowers have a curious resemblance to Lily flowers in form, and a curious resemblance to some Orchids in their strange markings and purplish coloring. They combine extraordinary form and lurid coloring with a somber beauty to a remarkable degree". Numerous people have mistakenly asked what the unusual orchid is growing in our shade beds, as toad-lilies do truly resemble a miniature orchid. The flowers are usually white and are speckled with purple markings.

I suggest that you site toad-lilies relatively near to a path or viewing area, as you will want to inspect their extraordinary beauty up close. I front them with the dwarf Chinese astilbe, Astilbe chinensis var. pumila as this astilbe not only enjoys similar growing conditions, but will still be at peak bloom when toad-lily starts to flower. The deep magenta pink flowers of the astilbe are complemented nicely with the unique toad-lily flowers arching over them. Other combinations that I personally use with toad-lilies are ferns, especially cultivars of the male ferns, Dryopteris filix-mas and some of the shield ferns, Polystichum braunii and P. polyblepharum.. Toad-lilies also combine well with certain hostas. At home, I have toad-lilies growing among Hosta "Krossa Regal" with excellent results. Even though several horticultural references say toad-lilies require damp growing conditions, I have found quite the opposite and feel that they are, if properly sited and supplied with summer mulch, drought tolerant. An added benefit is that the plant will self-sow and, contrary to the literature, can be divided in early spring.

Enough for this week; back to work getting ready for our plant sale where toad-lilies and hundreds of other plants featured in the IES Perennial Garden and Fern Glen will be on sale at prices that can’t be beat.

Brad Roeller
Manager of the IES Display Gardens

Week of 20 September 1999

(On hiatus, regrouping after the Fall Plant Sale)

Week of 27 September 1999

Before I get into highlighting plants in the IES Perennial Garden, I would like to thank all who generously supported last weekend’s annual Fall Plant Sale. Your purchases go a long way in sustaining the Display Garden program here at IES. Thanks from all of us!

Several visitors, and IES staff, have asked what the lovely bulb blooming by the beginning of the brick path system is. The bulbs are Crocus speciosus, an underutilized plant within a small, but exclusive group of bulbs that flower in the fall. I feel that this crocus is by far the best of the fall flowering species because of the size of the flowers. While it comes in several attractive shades of lavender, blue, purple and even white, what we exhibit is the more common violet blue form. The more common fall flowering crocus, C. sativus, is the original saffron crocus whose long, red, showy stigmas are used for flavoring and coloring food. This bulb is only marginally hardy in our growing zone, USDA zone 5. The other major fall flowering bulb is Colchicum autumnale often referred to as ‘Autumn Crocus’ because of its autumn blooming, cup-shaped flowers. Both bulbs have foliage that appears in the spring, dies back in mid-summer only to have the welcome flowers arise this time of year.

Crocus and colchicum are actually corms. Corms are often called bulbs by gardeners, but are actually bulblike stems. If a corm of a crocus is cut open, it will be found to be solid, and not made up of a number of swollen scale-like leaves, as is a bulb. The solid portion is the swollen base of the previous season’s flowering stem. It is covered on the outside with the shriveled remains of former leaf bases, and bears one or more buds towards the top. These contain the miniature leaves and flowering stems that will grow after the corm is planted. A circle of undeveloped roots is visible on its lower surface. All cormous plants produce cormels, tiny corms that develop from the bases of larger corms. These cormels can be used to propagate desired plants. We simply lift the desired plant when the foliage has withered but is still visible, remove the cormels, which will ring the outside of the "mother" corm, and replant the "mother". I usually prepare a shallow trench in a nursery bed and plant the cormels 1 to 2 inches deep and 2 to 3 inches apart. In their first year they will produce narrow, grasslike foliage. After the first growing season in their nursery bed, I’ll usually plant the corms where I want them in the garden. This is a much faster method of propagation than starting cormous plants from seed as it often takes several years for seed-propagated bulbs to flower. The above method of separating cormels from the corm is applicable for the spring and summer flowering cormous plants such as spring flowering Crocus, Erythronium, Gladiolus, Liatris spicata, Tritonia and Crocosmia. In the case of fall flowering corms, you will want to do the separating of the cormels after the flowers have withered.

Next week I’ll cover some tips on successful bulb planting.

Brad Roeller
Manager of the IES Display Gardens

Week of 4 October 1999

This week I highlight two of my favorite mid-western natives: Boltonia and Helianthus salicifolius. Both low maintenance perennials have been in flower for the last week or two and will continue to show off for some time to come.

Boltonia asteroides is a close relative of Asters and are indeed routinely mistakenly identified as an Aster. The cultivar we display all along the eastern side of the arbor is B. asteroides "Snowbank", fittingly named as the flowers when viewed at a distance, appear to be banks of snow. The name Boltonia is both the scientific and common name that commemorates the venerable English botanist, J. Bolton. This plant certainly qualifies as a low maintenance perennial as it is virtually maintenance-free. Boltonias will grow in ordinary garden soil, have low fertility and moisture requirements, and are insect and disease resistant. Also, unlike other tall-type asters, "Snowbank" does not require staking and seems to stay around 4 feet high regardless of the growing season. The only maintenance that the plants require is occasional lifting and dividing as they are somewhat vigorous and spread quickly. The divisions I get from the single Boltonia I grow in my home garden are much sought after amongst neighbors and friends! I find all parts of the Boltonia valuable. The linear, gray-green leaves can be up to 5 inches long. The multitude of flowers each plant offers is truly amazing. The flowers are what we describe as borne on loose indeterminate panicles.

Well, a little botanical terminology is in order: A panicle is a branching, indeterminate inflorescence, with more than one flower per branch. An inflorescence describes a grouping of flowers in a definite pattern, such as a panicle or an umbel. And an indeterminate inflorescence is one in which the youngest flower is borne at the end of the main axis or stem, and in the case of Boltonias, will continue to produce new flowers terminally or at the ends. This characteristic manifests itself in the aforementioned multitude of what appears to be never-ending flowering. I've tried counting the individual flowers on a single Boltonia and gave up after counting literally hundreds!

Another member of the Composite, or daisy family, is Helianthus salicifolius, one of our many native sunflowers. The name Helianthus is derived from helios, the sun, and anthos, a flower. The species name, salicifolius, describes its willow (genus Salix)-shaped leaves (folius). This sunflower with no common name ranks among the tallest perennials in the IES Perennial Garden. Even in this record-setting drought year, the tops of the plants reach close to 8 feet! In spite of its height the plant usually doesn’t require staking. We interplant this tall sunflower with equally tall plants such as Miscanthus sinensis cultures such as "Silberfeder" the "Silver-feather" Maiden Grass and other tall sunflowers like H. decapetalus, the thin-teaf sunflower. You can’t miss this tall yellow flower with narrow leaves growing across from the Poisonous Plant Bed. Like Boltonias, this sunflower will grow in ordinary soil in full sun to partial shade, nor is it demanding in-so-far-as moisture and fertility requirements. Be careful with all perennial sunflowers as they can be somewhat invasive and overpower companion plants.

Brad Roeller
Manager of the IES Display Gardens

Week of 11 October 1999

I’ve been gently reminded that in a previous "Highlights" I promised readers I would cover bulb planting. I can’t believe that this slipped my mind as we have been readying for this annual event for the past week. Now that we have had our first "killing" frost of the season, we definitely are ready for fall bulb planting. So, in a departure from the usual format of highlighting plants in bloom in the IES Perennial Garden, lets talk bulbs!

I truly enjoy planting bulbs in the fall because they are harbingers of spring. As mentioned above you must wait until a good frost or two before undertaking this task. Typically, our planting window for spring flowering bulbs is from late September through mid October. I always try and plant my tulips last so as to avoid "tulip fire", where new grow is sent up and exposed to freezing temperatures resulting in "burning" of the foliage.

Preparation is key to long-term success with bulbs. My wife thinks I’m crazy when she observes the amount of time I put into soil preparation for my bulbs. She is consistently taken aback the following spring with the burst of color in the garden before the rest of the garden "awakes". First and most importantly, bulbs require excellent drainage. Don’t plant them in low-lying areas; rather choose sites that are sunny and somewhat elevated. Some of the best bulb displays are on hillsides. If your soil is naturally poorly drained, amend it with generous amounts of sand and/or compost to improve drainage. I find it advantageous to dig out the whole area where you are planning to grow your bulbs. The depth you have to dig is dependent upon the size of the bulb you are planting. Generally, bulbs should be planted about 3 times as deep as their diameter. I incorporate generous amounts of well-aged manure or compost into the bottom of my planting hole. I also dig in a combination of bonemeal and a bulb fertilizer such as 8-8-8 into the bottom of the planting hole. I "screen" with a ¾ inch screen (this is what gives my wife a chuckle) the backfill soil to dispose of golf-ball sized and larger stones. I also amend the backfill with compost, about 1/3 by volume. I place bulbs firmly is the loose soil with the pointed ends up, and carefully place the backfill material so as not to disturb the bulb placement. I generally plant a minimum of 10 bulbs of each variety in my flower borders and 50 to 100 bulbs in landscaped areas so as to make a strong visual statement. Now, I want to stress that the above preparation is somewhat rigorous, however, I’ve been rewarded with over 14 years of enjoyment from some of my bulb plantings which I’m sure is due to this preparation and yearly bulb maintenance.

In no particular order, here are some tips I’ve learned from years of gardening with bulbs:

• For those of you who are plagued with rodents (i.e. squirrels, chipmunks, voles) eating your expensive bulbs, try this procedure: In the top few inches of soil backfill incorporate a combination of dried bloodmeal and crushed oyster shells (both available in any garden center). The smell of the bloodmeal and the texture of the oyster shells discourage rodents from digging. For voles, which can destroy tulip plantings, I use either one of two products: Ropel or Mole-Med. Both are likewise readily available.
• Plant Muscari (grape hyacinths) to outline your bulb plantings as its foliage naturally pokes up in the fall and persist through the spring to locate your bulb plantings so you won’t inadvertently dig them in the planting season.
• Don’t cut back or tie the foliage of your bulbs into cute "braids" until it has turned brown or yellow. This saps energy from the plant at a time when it should be going directly into next year’s display.
• Don’t allow seed heads to develop for the same reasons as above.
• If you fertilize your bulbs in the spring, do so early, just when you observe the foliage starting to poke through the soil surface. The most important fertilization is right after the bulbs flower and then again late in the growing season with a specialized bulb fertilizer.
• If you plant bulbs in the same location year after year, as is the case with some tulip plantings, you should treat the soil with a soil fungicide such as Subdue or Terrachlor to discourage fungal rots.
• Try naturalizing small or "minor" bulbs in lawn areas or open woodlands. I like to dig and lift a square foot or so of lawn and place groups of 25 to 50 minor bulbs such as Crocus, Snowdrops or small Daffodils. I just mix my combination of bonemeal and fertilizer into the bottom, place the bulbs, and replace the sod.
• Daffodils are excellent for both naturalizing and in formal settings. Most are very long lived, and the deer avoid them like the plague! I have never seen a deer or rodent browsed daff. If you use daffodils in a formal setting, best combine them with a companion perennial such as daylilies, to "hide" their foliage and provide two-season interest.
• Tulips and Hyacinths are best used in a formal setting as they are usually disposed of after they flower. However, some of my favorite tulips are species tulips, which are extremely long-lived. Try tulips such as Kaufmanniana, Fosteriana, and my favorites,Gregii. Some of my cultivars of these species have put on fabulous shows for over 14 years.
• Try layering bulbs in the same planting hole. Plant Grape Hyacinths, Crocus, Anemones and other small bulbs to add depth and color accents to your bulb display.

So, get out there and plant some bulbs! Dollar for dollar they are the most cost-effective perennials in the landscape.

Brad Roeller
Manager of the IES Display Gardens

Week of 17 October 1999

Last week visitors and staff were somewhat surprised with my unusually cheerful nature. This disposition had to with the arrival of our first "killing" frost. This seasonal occurrence always leaves me upbeat because the awe-inspiring fall color is close at hand, and the daily maintenance in the garden has been greatly reduced!

However, there are some garden tasks that should now be undertaken to insure the survival of tender garden favorites such as Cannas, Dahlias, Caladiums and Gladioli. If left to overwinter in the garden, they would almost certainly die. I must admit that I have enjoyed "breaking the rules" by having my favorite Calla lilies overwinter in my garden year after year. Actually, Callas aren’t lilies at all; rather they are tropical plants of the Arum Family, Araceae. Calla lilies shouldn’t be able to survive winters north of Washington DC, but, with a few "tricks" you can "buck" the gardening reference books. By my planting the tubers (actually rhizomes) deeper than normal (about 10-12 in. below grade), and siting them adjacent to the south side of my block foundation (taking advantage of this warm "microclimate"), and mulching them copiously with screened compost for a winter mulch (as you would do with hybrid roses), they grew and multiplied! However, this is not the norm and I recommend the following tips for preserving your favorite rhizomes and corms year after year:

For Cannas, members of a small tropical family, Cannaceae, we employ the following method: After a thorough frosting we carefully lift the rhizomes out of the garden, leaving a good amount of soil around them. We select the proper size pot and plant them with the "eyes" about 2 inches below the surface in dry potting soil. Do not water the pots; rather store them in a protected spot such as an unheated garage or cellar where they won’t freeze. The ideal temperature is 50-60° F. Save your whiskey barrel planters or large ceramic pots to accommodate the large rootstock as Cannas are better divided in March or April. We often get 6 to 8 or more divisions from a single Canna that has enjoyed a great, unfettered growing season in our display beds. In early April we carefully lift the rootstock, and cut it apart with as much tissue as possible around 1 or two growth buds. We pot them in a sandy soil and move them into a warm room (i.e. 70° F.) and start to water. Plant outdoors after danger of frost. Cannas enjoy rich, composted soil, generous watering and an occasional feeding.

Dahlias are likewise lifted after they have been well frosted. However, with Dahlias, you will want to dry them outside on a sunny day in the open air for several hours. I dry my tubers upside down to assist draining the "sap" from the stems. After drying I shake or lightly dust the dirt off the tubers, and dip them in a solution of 10 parts water to 1 part anti-desiccant (such as Wilt-pruf or Vapo-Guard). I store the tubers on an earthen floor in a cool, frostproof cellar. If such a location is not possible, tubers may be placed in cardboard boxes in a frostproof place. If stored in a heated cellar, where the air is dry, cover the tubers with peat moss, sand, or vermiculite; or wrap in newspapers to prevent drying, especially if you have not dipped the tubers in an anti-desiccant. Dahlias can be planted out in the following spring after danger of frost. When dividing clumps of Dahlias it is important to remember that the new growth is produced from the base of the old stem, not from the actual tuber, so that it is essential to secure a portion of old stem with each division. Also when dividing either Cannas or Dahlias, use a sharp knife and dust each cut with powdered sulfur or lime to prevent decay.

We really enjoy our Caladiums and Colocasias (elephant’s-ear) as they impart a tropical feel to our display beds. After experimenting with several varieties of each, we value the ones we exhibit and make every effort to save them for future displays. Both genera are members of the Arum family, and require the same treatment in-so-far-as overwintering as Cannas. Caladium is often grown in pots for patios or indoor use. If kept in pots the overwintering regime is somewhat different: Towards the end of the summer when the leaves begin to fade, we gradually reduce watering. I employ a method of overwintering espoused by T.H. Everett, the former Director of Horticulture at The New York Botanical Garden, and author of the comprehensive Encyclopedia of Horticulture. Once the leaves die down (before a frost), we store the pots in a cellar or other dry, moderately warm place until March when the tubers should be started into growth. To do this, carefully remove the tubers from their pots and shake as much old soil from them as possible. Set the tubers in flats of aged leaf compost or peat moss and cover them with similar material. As soon as roots are forming freely take the tubers out of the flats, divide if desired, and pot in 4 inch or larger pots. After potting keep them in a warm, moist atmosphere, shaded from hot sunshine, syringed (i.e. misted) and carefully watered until the roots reach the sides of the pots; then repot them in 6 inch pots or larger, according to size and vigor.

For those of you who grow Gladioli, their overwintering treatment is similar to the preceding plants. After a killing frost, the plants should be lifted and the stems cut off to about 1 inch above the corms. I usually store the corms in a garage for several days in order to easily remove any remaining soil. As mentioned in an earlier "Highlights", the cormuels of plants like Gladioli may be removed, stored separately, and planted in flats or a nursery bed to continue the varieties you like. I store the corms in paper bags in a cool, dry, frostproof place for the winter.

Brad Roeller
Manager of the IES Display Gardens

Week of 25 October 1999

In this week’s "Highlights" I will be covering a garden task that should be initiated around this time of year: preparing landscape trees and shrubs for the winter season.

Now that woody plants have begun to prepare physiologically for the dormant season, I like to perform a few simple tasks to help them through until growth begins in early April. Once I am assured that the growing season is winding down (a check of the IES Weather Station’s Growing Degree Days data is helpful), I undertake the following tasks:

• Make sure that the root zone is thoroughly watered. Thanks to record breaking September rainfall, the soil moisture level is at an optimum for plants going into the dormant season.
• Spread a layer of well-aged mulch over the entire root zone of the plant. Use the "drip edge" of the canopy for a minimum perimeter. I like to spread about a 4-inch layer, no more, no less. Remember not to spread it immediately adjacent to the stems of trees as the mulch will soften and potentially cause rotting of the bark. Bark compromised in this manner offers excellent sites for insect or disease entry.
• Check the pH of the soil. If it is not at the optimum growing range for the individual plant, now is an excellent time to adjust the pH. Soil amendments used to adjust the soil acidity take time to work, and winter snow melts are a great vehicle for getting the amendments down into the root zone. Use lime to raise the pH and sulfur to lower.
• The dormant season is an excellent time to feed woody plants. I use only organic fertilizers on woody plants and apply them as per label directions before I spread the winter mulch. Note: if the N-P-K (the three numbers on the fertilizer bag, i.e. 10-6-4) adds up to more than 15, the product is probably not totally organic. I like to use a fertilizer that has a higher phosphorus percentage (i.e. the middle number), such as 4-6-4 to encourage root growth. Woody plant roots will continue to grow and function right up until there is permanent frost in the ground. By spreading a mulch layer, you will achieve an extra few weeks or more of root growth that will help get the next growing season off to a better start. (I’ll cover fertilization and the use of the "new" biostimulants in upcoming "Highlights").
• October - November is a good time to undertake selected pruning in the landscape. However, improper pruning does more damage than no pruning at all. Before you make a cut, you had better be sure that there is a reason for it. We might prune to train a plant, to control the plant size, for appearance, for health, for production, to rejuvenate a plant or for special uses such as windbreaks. I’ll likewise cover various aspects of pruning in future "Highlights". Generally, I recommend not to prune landscape trees at this time of year because studies of wound repair in bark indicates that barrier zones in live bark are formed most rapidly at times of the year when other growth is also occurring. No wound repair occurs when trees are dormant. For this reason I limit my fall pruning to plants such as roses, clematis, hydrangea, buddleias, and many other shrubs.

Brad Roeller
Manager of the IES Display Gardens

Week of 1 November 1999

Are you tired of replacing roses each spring? It surprising how few people realize that most popular garden roses are grafted roses and not hardy in our northern climes. After a few more heavy frosts, I’ll start protecting the roses in the Shankman Rose Garden to insure their survival throughout the long winter season. Here are a few tips that you might want to try on your favorite rose:

• It is very important to remove the rose leaves from the rose beds. We also remove any remaining leaves still attached to the canes. The foliage is the prime overwintering habitat for fungal spores. Do not compost these leaves, either burn them or remove them a considerable distance from you garden area.
• Cut back the rose canes to a consistent 18 to 24 inch height. Do not do any additional pruning as this task is best performed in early spring. Even though rose cane borers are not present at this time of year, we still seal cuts that have a greater diameter than a pencil with grafting wax. This will hopefully reduce the number of future entry sites for the insect.
• On a good drying day, spray the denuded canes with an anti-desiccant such as Wilt-Pruf or Vapo-Guard. This will help in reducing the drying of the canes due to winter winds. The more viable canes we have next spring, the better the roses will be.
• The final task to perform is mulching the bushes for the winter. As mentioned earlier, most popular garden roses (i.e. hybrid teas, floribundas, and grandifloras) are grafted to winter-hardy rootstock. If left unprotected, the scion (the above-ground portion of the plant), would almost certainly die, while the stock (the below-ground hardy rootstock) will most likely survive and sometimes send up its own growth. Each spring I usually get a sample of rose foliage from a mystified rose owner whose rose has "reverted" back to the stock plant. The stock is usually obtained from species roses that have compound leaves that look nothing like the scion’s foliage. We also recommend planting the graft unions an inch or two below grade to further protect this susceptible part of the plant. Back to winter mulching: After years of trial trying to find the "perfect" mulch, I think I’ve come up with a good recipe: I mix together 50% by volume screened compost and 50% coarse sand. I get my compost from McEnroe’s Organic Farms as their compost is 100% weed and disease free, drains well, and is totally organic. The sand is actually "highway sand", the same stuff the highway departments sand the roads with in winter. The purpose of the sand is to further facilitate the drainage of the medium, to provide some heat-holding capacity of the mulch, thus reducing the intensity of the freezing around the graft union and canes, and to provide "structure" to the medium to enable me to form the typical "pyramids" over the rose bushes. Basically, I pour this mix slowly over each rose bush using a 5-gallon pail letting it seek its own "angle of repose" or angle that it will stack naturally. I average about 1.5 to 2 bucketfulls per bush. It looks like small pyramids when we are finished. One final tip: If you are in an exposed location you might want to erect a burlap wind screen a few feet from your roses to further reduce the desiccating effects of those January winds.

Brad Roeller
Manager of the IES Display Gardens

Week of 8 November 1999

"What plants should be cut back for winter?" and "When is the proper time to cut back perennials?" These are the current frequently-asked gardening questions of IES gardeners.

There are no hard and fast rules about cutting back perennials for winter preparation. Some "experts" offer that there is no need to cut back plants once they have been frosted, after all, there is nobody to cut back plants in the "great outdoors". I generally agree with this philosophy and recommend that indigenous natives do not need cutting back in your garden. We generally leave our ferns, woodland natives, and open sun loving plants "unmolested". Additionally, the seed heads of the coneflowers and black-eyed Susan make an excellent food source for our overwintering bird population.

This generalization does not hold true for many "exotic" garden plants. By not cutting back the foliage of popular garden plants such as peonies, phlox, and roses you may be unknowingly leaving a convenient overwintering habitat for diseases such as botrytis (gray mold), blackspot, and powdery mildew. This is not true for all exotic popular garden plants, but I always err on the "cutting back" side when determining which plants to defoliate. Another consideration that holds true primarily for exotics is that they often make a convenient nesting site for small rodents. As much as we enjoy our ornamental grasses, especially the majestic Miscanthus, the dense foliage offers safe refuge for the bane of all small garden rodents, the meadow vole. With gardens that are adjacent to "wild" areas (i.e. woodlands, fields, unmowed areas), the meadows voles will "move into" landscaped areas to feed on the tender, fleshy stems of garden plants such as Siberian iris, sedums, and ornamental grasses. The dense foliage offers a perfect foil to the natural predators of these pests, fox, coyote and hawks and owls. The cleaner you can leave you garden in the late fall, the more efficient these natural controls will be. We do leave a few "isolated" grass specimens in the garden for their winter interest.

When to cut back perennials is really a "no-brainer". Let Mother Nature tell you. Generally, plants that are frost-sensitive should be cut back first, while the plants that enjoy this time of year can wait. Some of the early spring blooming plants enjoy the cool nights and are still growing. The same holds true for the late fall blooming perennials. I noticed we still have bloom on our monkshood and gentians! As long as the plants are green, they are photosynthesizing and storing sugars for next spring. Cutting back too early may also prompt a new "flush" of growth, which, from a physiological standpoint, is detrimental to the plant.

How high to cut the plant back is likewise prompted by common sense. I suggest that you cut perennials back to an inch or two in height for two reasons. First, the stems will provide a visual "marker" so you won’t be inadvertently stepping on tender plant crowns. Also, this low height will not "catch" leaves as much as uncut foliage or foliage that is several inches high. I like to avoid "pockets" of leaves over plant crowns as they hold snow and moisture, which in certain plants can lead to rotting of the crowns and death of the plants. Subshrubs such as Russian sage, lavender, and butterfly bushes I cut back in early spring. More on that in a future "Highlights".

Brad Roeller
Manager of the IES Display Gardens

Week of 15 November 1999

Gardeners, if you haven’t planned your strategy for protecting your favorite landscape trees and shrubs from deer browsing, it’s not too late. Shortly, deer will be targeting their "traditional" winter browse sources. Even though you have been seeing deer out grazing in the fields that are green and succulent, as winter approaches deer will be ingesting more and more woody buds and growing tips as part of their diet. By mid winter the largest amount of their diet will consist of woody stems as compared to herbaceous grass. This is especially true once we have prolonged snow cover. Deer have adapted to digest a greater percentage of woody browse during the dormant season because the quality and availability of herbaceous food is less during the winter. So be prepared, as I noticed this winter-type browsing just last week. I should point out that deer will browse certain woody plants during the clement season. These plants seem to be primarily members of the Caprifoliaceae and Saxifraga families of plants such as mock orange, all of the hydrangeas, Diervillas,, Weigelas, Diervillas, etc. When we have drought years like this past summer, deer will browse, sometimes extensively, on succulent new woody growth as the nutritional quality of the natural summertime food, grasses and forbes, is severely diminished. What I term "traditional" wintertime browse consists of trees and shrubs that are not selected for food during the growing season, but are once the dormant season is upon us. A partial list of popular landscape trees and shrubs in this category would include: all Rhododendrons, arborvitae, yews, hollies, mountain laurels, as well as all the plants that may have been browsed upon during the growing season. Enough on this as visitors to IES can get all this and much more from the Institute’s brochure, "The Deer Browse Garden" along with the yearly "Year-End Reports" which highlight plants that are not selected by deer for food and evaluates protection measures employed year round.

The following are some tips for protecting your favorite landscape trees and shrubs from "winter" browsing:

• When you plant any new tree or shrub in your landscape, regardless of the time of year or browsing pressure, spray it with an odor and/or taste repellent. If you can "imprint" an unpleasant experience with your "local" deer herd at the outset, there may be less browsing upon it during the winter.
• Try and predict the browsing pressure beforehand. If we have had a summer drought and/or the fall mast crop (i.e. nuts and acorns) is poor; deer will be relying perhaps more on the "potpourri" of tasty garden plants. The same holds true for snow cover. If long range forecasts call for significant snowfalls, traditional protection measures may not work. When deer are under stress due to lack of natural food sources (i.e. natural woody stems, nuts, acorns, green grass), no amount of deer repellents will work. Additionally, flimsy physical barriers such as netting, burlap, and electric fencing will likewise fail. So become an environmental "forecaster". Note that I’m expecting unusually heavy browsing pressure as we had a record-setting summer drought, very poor mast year, and are due for a "real" winter. I’m not going to rely on chemical spray-on repellents to be effective.
• I prefer to use burlap stapled securely to wooden stakes. I employ 45-inch high burlap. If deer can’t see the plant, they will usually not try to get to it. Do not "wrap" your plants with burlap as this can lead to leaf damage from freezing.

Brad Roeller
Manager of the IES Display Gardens

Week of 22 November 1999

In last week’s "Highlights" I began a discussion on protecting landscape trees and shrubs from wintertime deer browsing. I am going to conclude this area of interest with some tips for using chemical sprays for repelling deer from feeding on valuable plant specimens.

Basically there are two classes of chemical deer repellents: odor based and taste based. I’m amazed with the proliferation of new deer repellents over the last few years, no doubt a market-driven phenomenon. Both types of repellents can be quite effective if properly applied and the browsing pressure is not inordinately great. As mentioned last week, if deer are approaching starvation no amount of any class of repellents will be effective in deterring deer from feeding on sprayed plants. Using chemical repellents is kind of like a "craps shoot": sometimes you win, often you lose. Over the years of evaluating the effectiveness of chemical repellents, I have found that in the years that deer are not under stress (i.e., open, mild winters, good mast crops and moderate deer populations) it is not uncommon for some of the better repellents to be 100% effective for the duration of the winter. Other years, when the deer herd is under stress, I have witnessed severe browsing within days of applying chemical spray repellents. As I alluded to in last week’s "Highlights", try and become an "environmental forecaster" to predict the browsing pressure going into the winter season.

Some tips on using chemical repellents:

• Always apply as per label directions. It is important to apply when the air temperature is above 40°F for the full drying time of the product. If the product freezes of the leaf surface, phytotoxicity, or leaf tissue damage, will be the results. You know how long it takes laundry to dry outside in winter; it is the same with repellents. Often the "magical" 40°F threshold must remain for 4 to 6 hours. This is one of the primary reasons why I don’t depend on chemical repellents alone for my plant protection program; these warm drying days may not exist for weeks in January or February.
• With your soap-based repellents like Hinder, thoroughly shake the container, pour out the desired amount into your measuring cup and wait for the product to settle out before adding it to the water in your sprayer. You will usually have far less measured product if you add the frothy, unsettled soap directly to the tank.
• Even though the thiram based repellents are among the best (Chew-Not, et. al.), avoid these products as thiram is a potent fungicide that is easily absorbed through unprotected skin. I understand that there is a movement to remove thiram from the market.
• Alternating your products may be a good idea. While I have no definitive proof of this, I have noticed that there may be something to this in my studies of repellent efficacy in the IES Deer Browse Garden.

The most effective spray repellent utilized in the Deer Browse Garden last winter was a combination of repellents. Plants that were sprayed monthly from late October until April with a "hot" sauce (I used a product from Miller Chemical Company, Miller’s Hot Sauce) combined with a scent dispensing urine repellent (I used fresh coyote urine), were virtually unbrowsed. The results of the protection program will be found in the forthcoming IES Deer Browse Garden’s 1998-1999 Annual Report.

Please note: The next "Highlights" will be out on November 29,1999 as I will be out "managing" the deer herd with the most effective means of browsing deterrence, a shotgun!

Brad Roeller
Manager of the IES Display Gardens

Week of 6 December 1999

I must apologize to faithful "Highlights" readers, as I’m a week behind in this weekly task. This inconvenience is due to my lack of success in "harvesting" an adult female deer as part of the Institute’s annual deer management program. I’ll keep at it and hopefully contribute to this time-proven management tool intended to keep the local deer herd at a reasonable size.

What to do in the garden this time of year? Thankfully, not much! Mulch your roses if you haven’t done so already. It’s also a good time to feed and mulch your landscape shrubs. I like to use a totally organic fertilizer such as North Country Organic’s Pro-Gro or Espoma’s Plant or Holly-Tone. By using a low nitrogen, slow release fertilizer and applying a 3 inch mulch layer, the shrub’s roots will continue to actively grow right up until there is deep frost in the ground. This really gets the plants off to a great start in the spring when soil temperatures start to warm. Because of the recent heavy November rains there is adequate ground moisture for the landscape plants, so no need to do the final deep watering of the season.

For those darn oak leaves and leaves from introduced exotics that always seem to hang on the branch longer than our natives, blow or rake them from the garden beds. They always seem to accumulate in the foliage and crowns or perennials or in corners of walls or other garden structures. Leaves are not a good winter mulch as they collect and hold the moisture from winter rains or snow which can lead to crown rot on certain sensitive perennials. I do however like to "blanket" the garden with one of two wintertime mulches. The first method employs laying an inch to two-inch layer of leaf compost or old spruce bark mulch over the entire garden. By cutting back the perennials to an inch or two above the ground you are able to see where they reside. Do not cover the crowns of the perennials with this layer of mulch, and avoid creating "pockets" where water will collect over the crowns of the plants. Remember, now is a good time to adjust the pH of your soil before you lay down the mulch. An alternate method is to cover your garden with a layer of evergreen bough. This should be done late in the season (never before Thanksgiving in our area) once there is frost in the ground. I like to get left over Christmas trees for this job as spruce and fir branches lie flat and cover large areas. Importantly, plan your route in and out of the garden beds this time of year, as stepping on frozen plant crowns is almost certain death for the plant. This is why we don’t cut plant foliage back completely to the ground but leave an inch or two to indicate the position of the plant. There is no problem in putting boughs down over "poor man’s mulch", snow. Plants don’t like extremes; they like a slow warm-up in the spring. The winter mulches will moderate soil temperatures and delay the initiation of growth in the spring thus reducing the potential for spring frost damage. Additionally, the mulch will reduce the tendency of frost heaving and subsequent crown damage to shallow rooted perennials. This phenomenon is common in December and then again in March and April, especially when there is no snow cover.

So enjoy the season and start to think about next year’s display. It’s a great time to leaf through garden magazines and seed catalogues to get some ideas for next year

Brad Roeller
Manager of the IES Display Gardens

Week of 13 December 1999

This is a good time of year to spend some time pruning your shrubs. We aren’t yet in the "dead" of winter and we haven’t experienced any serious snow. With the foliage off the shrubs you are better able to see the shape and arrangement of the branches, which makes pruning an easier chore.

(I avoid pruning my landscape trees during the dormant season. Studies of wound repair in bark of several different species of woody plants indicate that the barrier zones in live bark are formed most rapidly at times of the year when growth is also occurring. No wound repair occurs when trees are dormant. Because pruning cuts are wounds, and wounds are known to be sites for origination of canker diseases and wood decay, the prudent gardener will prune no more often than is absolutely necessary and will do it at a time of the year when the plant has the best chance to repair the damage. Alex Shigo’s work on tree response to pruning and the subsequent compartmentalization of wounds has revolutionized arboricultural pruning practices. Therefore, pruning trees from early spring through midsummer would seem to be the best time for such action and pruning in the beginning of the dormant season, i.e., November and December, is to be avoided as much as possible. More on tree pruning in upcoming "Highlights".)

The first "rule" of pruning is to always have a good reason for making a cut. Don’t prune for the sake of pruning. Most pruning is done for one or more of the following reasons: to train a plant, to increase fruit or flower production, for appearance, for health, for rejuvenation, to control plant size, or for special purposes such as a windbreak or sound barriers.

Most deciduous shrubs need pruning rarely, although sometimes it is beneficial to remove old wood periodically to rejuvenate them. This practice sometimes has the additional benefit of increasing flower and fruit production. I don’t worry about the aforementioned dangers of pruning trees in the dormant season as I'm removing entire stem from the plant and not doing very much pruning on individual remaining branches. I remove any broken, dead, or diseased branches whenever I notice them, regardless of the season of the year.

If I do perform serious pruning on branches left after the thinning out of the old stems that are past their prime, it is imperative to know if the plant blooms on wood produced the same year or on wood that grew during the previous season. Shrubs that bloom on year-old wood should be pruned just after the flower blossoms have faded. The plant will send up new branches forming buds that will bloom the following year. A partial list of popular shrubs that fall into this category are: barberry, smoke tree, Daphne, forsythia, beautybush, honeysuckle, mock orange, ninebark, Pieris, spring-blooming spiraeas, lilac, and Weigela.

Shrubs that form flowers on wood grown the same season should be pruned when the plant is dormant. Prune these shrubs before the buds show green. These include: Abelia, lead plant, Aralia, butterfly bush, beautyberry, heather, bluebeard, buttonbush, broom, Diervilla, euonymus, witch hazel, rose of Sharon, Hydrangea, Hypericum, cinquefoil, American elder, false spiraea, spiraeas that bloom in the summer, coralberry, tamarisk, Vitex.

As you can see, most spring flowering shrubs have evolved to bloom on "old" wood, while most summer and fall flowering shrubs bloom on "new" wood. If I am unsure of which category a plant falls into, I use July 4 (because I’m patriotic!) as a cut-off date: if they bloom before that date they will most likely be flowering on old wood, after that date the opposite usually holds true.

Brad Roeller
Manager of the IES Display Gardens

Weeks of 20 and 27 December 1999

The winter season is almost upon us and there is little to do insofar as garden tasks. This winter I will continue this weekly offering by giving "tips" on several aspects of gardening. Many of my recommendations will be in agreement with the established guidelines. However, some of the practices that I will offer will run counter to the accepted norm.

For the next few weeks I will talk about planting techniques for trees and shrubs. In my 26 years of gardening at the Institute, I have planted literally thousands of woody plants and have been able to evaluate the various factors that affect the long-term success in establishing woody plants in the landscape. These range from the type of plant you buy (i.e., container, balled and burlapped, bare root, etc.) to the actual techniques used in planting. Here are some of my "pearls of wisdom" when it comes to buying plants from nurseries:

Bigger is not better when it comes to buying plants. Some of the most successful trees and shrubs at the Institute have been purchased as, or placed in the landscape as young plants and seedlings, not the 10-inch+ caliper trees that make the "instant" impact in the landscape. Plants that are young have a much better chance of developing into long-lived specimens with sound branching and buttress root support structures when compared to those large, expensive mammoths that so many homeowners are paying big bucks to landscape their homes with. Young developing roots will better adapt to the existing growing conditions of the site leading to a more balanced "root-to-shoot" ratio. This means that the scaffold branching as well as the support and feeding root system will grow no more (or less) than the site will support. These trees will be the ones in your landscape that will withstand the snow loads and wind shears as well as other environmental stresses such as temperatures and droughts. I remember a planting done in the old "Arboretum" days that made a lasting impression on me. We planted 100 scarlet and red oaks in one area to develop as overstory shade trees. Fifty of the oaks were "bare root" 1-inch caliper whips, while the other half were expensive 2-inch caliper balled-and-burlapped 10+ foot tall nursery stock. The appearance of the planting was almost laughable. Intermixed were these robust "big" oaks with the "puny" bare root nursery whips that had minimal root and branching structure. Well let me tell you, today (almost 20 years later) the bare-root trees have outgrown their counterparts and have withstood "Snow Leaf", "Snow Bud", hurricanes, droughts, etc. much better than the balled-and burlapped trees. Large trees that have been reared in nursery blocks, with growing conditions and soils much different than where they will be planted, take much longer to adapt to their environment than young seedlings in their "formative" years. When trees are transplanted from the nursery they lose up to 90% of their root system. This translates into years of truncated annual growth due to the disparity of the root-to-shoot ratio. Sometimes this imbalance is never rectified and these trees languish at near their original size. My favorite method of landscape planting is buying "liner stock" and rearing them for a year or two in a nursery bed before they are transplanted to their "permanent" home. I can usually buy these young transplants for less than a dollar or two apiece, affording me the opportunity to broaden my landscaping "palate" with a wide selection of trees and shrubs for planting. Patience is a virtue when it comes to establishing woody plants around your home!

Much more on buying trees and shrubs and techniques for success in establishing these plants in your landscape next week.

Brad Roeller
Manager of the IES Display Gardens

Week of 3 January 2000

As promised, more on buying plants from your local nursery.

When shopping in nurseries or garden centers I make it a point to ask about the source of the plant(s) I’m interested in. Is it "home grown" or has the nursery shipped the plant in from a large wholesale nursery? I’m usually leery about purchasing plants, especially trees, from the "usual" big sources in the trade. Most of the huge commercial nurseries that supply our local nurseries and garden centers are located down South or out West (i.e. California) where the climate offers these establishments a much longer growing season, and subsequently a faster turn-around time in getting plants to the customer, than their northern counterparts. Plants coming from these regions of the country have been reared in a much different growing environment than the conditions they will have to adapt to when you plant them here in the Northeast.

One of the factors that can have a big impact, especially with nursery grown trees, is the soil that the plants have been grown in. A quick look inside the container or under the burlap may show the typical red southern clay or the sandy soils of the Mid-Atlantic states. These plants may have a tough time adapting to their new growing environment, i.e. the gravelly upland soils in our region. Another problem I often encounter when doing my early spring plant shopping for the Perennial Garden is the difference in the growing season between those southern or western nurseries and here in Dutchess County. Plants from Virginia or California are often a month or two ahead of the plants here in our hardiness zone. Buying plants in April at a local nursery that have just been shipped from a Californian nursery, where the plants physiologically think its June, can lead to problems. Late frosts, cool soil temperatures, and cool air temperatures can lead to problems such as "bud blasting", leaf and bark damage, and a much slower initiation of growth. Flowering time and other cyclic physiological plant responses can be affected. Whenever possible, buy plants that have been grown from a young age in conditions that are environmentally similar to where they will be planted. This is especially important when buying shade trees, as the cost of retail trees is scary. Shrubs, in addition to costing considerably less, usually have an easier time adapting to their planting site. Whenever possible I like to purchase plants that have been grown in a hardiness zone colder than ours. You can bet these plants will be winter-hardy.

There are several things I look for in plants when shopping at my local nursery. With trees, I’m concerned about what the plant is residing in. Is it balled-and-burlapped? If so, look closely at the condition of the ball. Is it still solid and symmetrical? Loose balls and/or squished or one-sided balls indicate potential problems with the root system. It is imperative the soil-to-root interface be firm. Without close contact with soil, roots will not survive. I also look at the type of burlap the root ball is wrapped in. If it’s synthetic or treated (look for the greenish tinge to the color of the burlap), you know that it will have to come off or be mostly removed at planting time. Taking off burlap when planting is sometimes next to impossible, especially if the tree is in a wire basket. As mentioned earlier, check the soil for a clue as to where it came from. Is the tree in a wire basket or is the ball hand-laced? I much prefer hand-laced balls to that of machine dug, wire basket stock (more on wire baskets when I talk about planting trees).

Next week: what to look for in container grown and mail order plants.

Brad Roeller
Manager of the IES Display Gardens

Week of 10 January 2000

Most nurseries and garden centers that I visit keep a wary eye on me as I’m invariably taking plants out of their containers before I make a purchase. What I’m most interested in is the condition of the root system of the plant. A healthy, symmetrical root system is the most important factor in successful establishment of plants in your landscape. By and large, growers leave plants in containers longer than is optimal for root development. With today’s soil-less potting mixes, especially the predominately bark-based mixes and the overfertilization of nursery stock, roots grow rapidly to the extremities of their containers. Rarely do I find a plant that is at the proper root-to-container ratio. The norm is a near impenetrable mass of roots that are struggling to exit the drainage holes in the bottom of the container. This may not deter me from purchasing the plant (I’ll pass on some tips on correcting root-bound plants next week when I talk about planting techniques), but if a particular plant in the stock is less root-bound, that’s the one I’ll purchase. When purchasing container-grown trees, it’s especially important to inspect the condition of the root system.

The root system of a tree is far different than that of a shrub. Trees develop a "buttress" root system that will physically support the tree as it grows in girth and height. Buttress roots are deep rooted and do not act as feeding roots except in times of drought (since they are deep rooted and often have access to deep ground water that surface-feeding roots may not). If trees reared in containers are left in these containers too long, the roots will hit the sides of the container and continue to grow, assuming the circular shape of the container itself. This often leads to a condition called "girdling roots". The only part of the root system that actually travels is the growing tips, or meristems, of the roots. These growing tips snake through the large pores of the soil. The roots also grow in girth. Thus if you plant a tree that has roots growing in a circular fashion around the stem, as the trunk and the roots grow in girth, eventually they will meet and the girdling roots will actually "strangle" the conductive cells of the trunk slowly "choking" off water and nutrients. Not a pretty situation! What I look for is an evenly spaced radial root system when I inspect container grown or bare root trees.

Those of us who like to purchase mail-order trees and shrubs should also look for certain things before they accept delivery. Note that I’ve maintained that "bigger is not better" when buying plants. This is why I like to purchase young transplants (cuttings or grafted stock planted in a small container) or bare-root plants (plants that come without soil, but have their roots packed in a moist medium). These plants, if of good quality and handled properly, will adapt to their site and perform better in the long run compared to their bigger nursery cousins. I want to receive plants that are moist, have no mold on the roots (if bare root) or upper growth, and, of course, have no obvious damage from shipping. Again, I want a root system that is not rootbound but radial in growth. If the plant has been shipped in a dormant state, you don’t have to plant it immediately. Just make sure that the plant is kept in a cool (35-45°F) dark place and the roots are kept evenly moist. If the plant is in leaf, it should be planted immediately. Bare root plants should only be accepted in a dormant state, not in leaf. I like to soak the roots of bare root plants in a bucket of tepid water to which I’ve added kelp or other biostimulants (more on these in an upcoming "Highlights") for 3 to 4 hours before planting.

Brad Roeller
Manager of the IES Display Gardens

Week of 17 January 2000

For the next several "Highlights" I’ll be discussing the proper methods of planting trees and shrubs. In thinking back about the multitude of woody plants I have planted, especially in the "Arboretum days", I amazed how basic planting techniques has changed. Unfortunately, I still see a lot of misinformation about planting being offered in popular gardening references. OK, lets get started.

First, and most importantly, is to choose the proper plant for the site. I know that sounds like a no-brainer, but I continually see poorly selected trees and shrubs for the site conditions they are placed in. An excellent reference that I use all the time to double check myself concerning hardiness, growing requirements and plant characteristics is Michael Dirr’s Manual of Woody Landscape Plants. My worn-out desk copy is a testament to its frequent use. Another noteworthy reference is Donald Wyman’s Trees and Shrubs for American Gardens. Check these out before you purchase your landscape trees and shrubs. I try not to act impulsively when it comes to landscaping. It’s so tempting to have an "instant landscape" by spending all your hard-earned money at your local nursery and plant a plethora of woody specimens to impress your spouse and neighbors! I like to "know" my property before I start willy-nilly placing plants in the landscape. I’m talking about conducting a thorough site analysis as part of developing a landscape plan for your property (check out the Landscape Design curriculum at the Institute’s Continuing Education Program). Spend a growing and dormant season to learn about the microclimates that occur on every site before you go out and spend hundreds of dollars at the nursery.

In my old house in the Village of Millbrook, I was able to have a thriving colony of calla lilies, Zantedeschia aethiopica, which are supposedly winter-hardy to zone 8 (we’re talking Deep South here!). By taking advantage of a southern exposure, a concrete foundation wall, and copious amounts of winter mulch, my wife had cut calla lilies all summer for the table. I’m also quite proud of growing a cross between the southern magnolia, Magnolia grandiflora (zone 6-9) and M. virgininana, the sweetbay magnolia by studying my yard and taking advantage of terrain and building locations to find a wind-sheltered, northern-exposed site. After two years of bud blasting on my favorite azaleas, I finally realized that these were placed in a frost pocket and moved them to a better exposure in my shrub border. The long and short of it is to know your property intimately before you start planting all over the place. Know the dynamics of wind movement of your property. Recognize the seasonal variations with sun and shade. Know where the underground utilities are! Where are the low spots where water collects? What areas get bypassed of rainfall because of slopes or dense canopies of overstory trees? Note the placement of existing trees and shrubs in your yard and how they will impact your new additions in-so-far-as light, and competition for water and nutrients. One of the most common mistakes in siting trees and shrubs is not taking into account neighboring shade trees and placing other dominant trees "under" the influence of the established shade tree. Phototropism comes into play, leading to trees with leaders growing towards the light and developing a leaning growth habit. Always look directly up when siting a major tree; you need a generous, clear avenue to uncontested light for proper canopy development.

Next week I’ll cover the soil. What soil testing and analysis should be done before planting? And I’ll finally lay to rest the controversy about adding soil amendments at planting time.

Brad Roeller
Manager of the IES Display Gardens

Week of 24 January 2000

Soil. My gosh, books have been written on the subject and I’m just starting to realize the importance of soil microbes and the intricate balance of the soil food web in maintaining healthy plants in the garden. [Incidentally, the Institute of Ecosystem Studies is having a wonderful speaker in this field participate in its Friday seminar series. On January 28^th, Dr. Elaine Ingham from Oregon State University will talk on "The Soil and Foliar Foodwebs" at 11:00 a.m. in the IES auditorium on Route 44A in Millbrook, N.Y. She gave one of the best talks I’ve heard in years on soil food webs and how pesticides affect the dynamics of the web.] Apparently, there is another microbial food web on the surface of leaves that impacts leaf health and functions. Great stuff, with invaluable lessons to be learned for conscientious gardeners. You might want to think twice before spraying your roses next year to control blackspot or powdery mildew, or Sevin to control thrips. If these typical fungicide applications lead to the death of up to 90% of the beneficial soil fungi, the ramifications to plant performance can be far-reaching over time. More on this subject in later "Highlights" when I talk about chemical use and the Institute’s Shankman Rose Garden demonstration.

I’m amazed that gardeners don’t investigate the physical and nutritional properties of their soil before they start planting. Some people just start planting while others buy copious amounts of soil amendments and fertilizers to work into the topsoil without knowing a thing about their soil. Soil is an aggregate made up of sand, silt and clay. What everybody wants is a loam; and unfortunately, unless they own a piece of bottomland, they are probably out of luck. Also, practically speaking, most soil around houses has been quite thoroughly disturbed during the construction of the house. The naturally occurring horizons are not present any more; but this "disturbed" soil does have physical properties that you should investigate. I like to do a "fractional analysis" of the soil to see the percentage of sand, silt and clay in the soil so I can classify it. It’s easy to do and you need no special equipment other than a jar and some non-sudsing detergent. Here is a source for the soil fractional analysis procedure and soil triangle that allow you to determine your soil type:

Rodale's Flower Garden Problem Solver, by Jeff and Liz Ball
Rodale Press, Emmaus, Pennsylvania c. 1990
ISBN 0-87857-868-4

The accepted wisdom concerning soil amendments for planting is to not add soil amendments (i.e. compost, manure, fertilizers, etc.). Let me tell you, this was (and still is) a tough pill to swallow. I was one to add copious amounts of compost and manure to planting holes and backfill when I plant a specimen tree or shrub. In reflection, I must admit the errors of my ways. In the early days of the Mary Flagler Cary Arboretum, we had access to tons of manure from local horse farms and would add generous amounts to our collection trees when planting. For the first 5 to 10 years the plants performed admirably, no doubt due to the organic amendments and periodic feedings. Depending on the rate of growth of the individual plants, they eventually outgrew their planting holes and the roots found the indigenous soil, i.e. Dutchess County topsoil ( gravel). The physical and chemical properties of the "virgin" soil are far different than that of the planting soil with ramifications that are, and will continue to be, far reaching. Structurally, the root system will be far different with possible weak support implications. Rates of growth, mineral nutrient uptake rates and other plant dynamics have been affected. More next week!

Brad Roeller
Manager of the IES Display Gardens

Week of 31 January 2000

As mentioned in last week’s "Highlights", the (new) conventional wisdom in planting techniques is not to add soil amendments to the planting hole and backfill when planting trees and shrubs. Just remove stones larger than baseball size from the excavated soil and plant away!

Just like the commercial for some make of car, "wider is better" when making the hole for your tree or shrub. Do not use the "shoehorn" approach when digging! A profile of a proper planting hole would be at least 3 times wider than the diameter of the ball or container of the plant. Importantly, the bottom of the hole should be no deeper than the height of the ball or container of the plant. I always inspect the ball before I dig the hole to see where the root-flare of the plant starts. You should never plant a tree or shrub with the root-flare below grade level. So often the soil has been mechanically lifted up and around the stem of the plant in the digging and balling process. I have seen balled and burlapped trees where I have had to remove 3 or more inches of soil from the top of the rootball to plant the tree at the proper height. It is so important not to plant trees deeper than the aforementioned root-flare, as more trees are lost to this phenomenon than to most other improper cultural techniques. Where the actual ball or container sits should be undisturbed earth, of the proper depth, while the surrounding hole can and should be up to a half foot lower than the shelf where the plant will sit. This will allow "loose" backfill to surround the root system facilitating unencumbered new root growth into uncompacted earth. Trees that have been planted utilizing the "shoehorn" technique with a hole that just accommodates the rootball or container are at a disadvantage as the newly formed tender roots will have a much more difficult time penetrating the "virgin" soil than will the trees and shrubs planted with the "wider is better" hole. I also loosen the surrounding ground outside my planting hole by sinking a spading fork into the ground in concentric circles around the hole out at least 6 to 8 feet. The distance between individual spading fork holes as well as the distance between concentric rings around the planting hole is usually about 2 feet on center. The purpose of this practice is to likewise loosen the ground within the future root zone of the plant.

When you purchase trees that have been dug in the nursery and placed in the popular wire baskets, it is imperative that certain additional steps take place to insure success in planting. Don’t let anyone tell you that it is fine to leave the wire basket in place when you plant the tree. I’ve had several so-called experts swear that this does no harm to the tree. From personal experience of planting literally thousands of wire basketed trees, that this is not the case! I’ve had 25 years experience with planting trees either personally dug or purchased utilizing wire baskets. For several years, depending on the growth rate of the individual tree, the plant may grow and flourish. However, at some point in time you may notice decline and death in certain species. These galvanized wire baskets don’t break down when placed below the soil surface. Fast growing trees will eventually be girdled by the baskets themselves over time. When planting wire-basketed trees I always remove as much of the basket as I’m able to, hopefully all but the bottom ring of wire. Additionally, whether you’re dealing with conventional balled-and-burlapped trees or wire-baskets, always remove as much of the burlap from the rootball before you backfill. Burlap, whether untreated, treated with a rot retardant, or, worst of all, synthetic, impedes the root growth. Because the decay process is slowed beneath the surface, it’s often years before the burlap is at a state where roots can easily extend through this barrier. So take it off! More next week!

Brad Roeller
Manager of the IES Display Gardens

Week of 7 February 2000

For the last several "Highlights" I have been discussing sundry aspects of purchasing trees and shrubs as well as the "latest" planting techniques. To summarize some of the key points: 

1. Whenever given the opportunity, purchase nursery stock that has been reared locally or in a hardiness zone colder than yours. Avoid the "Californian" or southern-grown stock, especially when purchasing large trees.
2. Start with smaller sized plants. Not only do they cost less; they will become better adapted to your site both initially and over the long haul. This will translate into stronger, more vigorous specimens that will outperform their larger counterparts.
3. Carefully inspect the plants in the nursery or garden center. With trees, look at the root flare: is it properly formed and symmetrical? If possible, look at the roots: is the color good; in containers, are they root-bound? Is the branching radial and evenly spaced in trees? Is there a strong, dominant central leader? Are there scars on the trunk or major branches from the digging operation? Check for insects and/or disease.
4. Have you properly analyzed your site before you start popping trees and shrubs into the ground? Is there a generous and clear avenue to light for shade trees to properly develop full canopies and straight leaders? What are the characteristics and properties of your soil? Are there drainage problems? Take advantage of the "micro-climates" that exist in every landscape. Wind tunnels, frost pockets, heat sinks, etc. all have impacts on the success or failure plantings. Most importantly, pick the "right plant" for the situation. While I love our native flowering dogwoods, they come with inherent maintenance problems (i.e. lower branch dieback). Bur oaks are one of my favorite shade trees; however, if you live on a ¼ acre lot, they are not for you as the tree will overwhelm your lot. When deciding what kinds of trees and shrubs would do well in my landscape, I like to travel around visiting gardens and estates to see what is performing well for them on sites similar to my own.
5. "Wider is better!" when digging the planting hole. Strive for a wide hole (3 times the diameter of the ball or container) and make a solid, undisturbed earth pedestal to set the plant on. Planting depth is paramount to the success of the plant. The root flare must be at or slightly above grade level. If planting wire-basketed or balled and burlapped plants, remove as much as possible of the wire basket and burlap from the top and sides of the ball once the plant is set is place.
6. Do not add soil amendments to the planting hole or backfill. Just discard baseball sized or larger stones from the backfill material. There is no need to fertilize trees and shrubs at planting time. (More on fertilization in upcoming "Highlights").

That's where we are so for on this topic. Next comes the actual placement of the tree or shrub into the hole. It's essential in the case of balled and burlapped and/or wire-basketed trees to handle them gently. Your prime objective is not to compromise the integrity of the rootball (i.e. cracking or crumbling the soil away from the roots). Luckily, most good nurseries either have or incorporate some clay into their soil which helps in the shaping of the ball as well as providing some structural integrity. Handle the rootball with "kid gloves"! Once placed, the next step is to "face" the tree or shrub and to make sure that it is set plumb. Evergreens often have a better side, one that is fuller or more symmetrical than the other. Decide which "face" you want to highlight before you place the tree in the hole.

Brad Roeller
Manager of the IES Display Gardens

Week of 14 February 2000

Continuing our discussion about planting techniques and tips:

With increasing frequency I'm finding container-grown trees and shrubs to be root-bound. With the popular soil-less potting mixes, which utilize bark as the main component of the mix, roots quickly outgrow their containers and start to spiral around the inside perimeter of the container. Most root-bound shrubs can be planted without serious ramifications. However, root-bound trees can develop serious problems down the road. As a matter of practice I correct all root-bound problems at planting time, regardless of the type of plant.

Take the plant from its container and with a sharp serrated kitchen knife "saw" through the root mass. Start near the top of the roots, cutting in only ½ inch or so, and continue to the bottom of the roots. The direction of the cut should be from top to bottom, but not straight. Curve or spiral your cuts so where you end up at the bottom of the cut will be 3 or 4 inches behind where you began the cut The idea is to start succeeding cuts at a point where you finished the last cut. This will form an even pattern of new roots that will "break" from the cut roots. This is a better technique than just having new roots break from vertical cuts spaced around the circumference of the rootball. Spacing of the cuts is largely dependent upon the size (diameter) of the rootball. I generally space my curved vertical slices about 6 inches apart. One last tip: Cut through the bottom of the rootmass by making an "X" pattern. This cut should be deeper than the "side" cuts as the rootmass on the bottom will invariably be greater than that on the sides of the container.

With balled-and-burlapped or wire-basketed trees, you usually won't encounter this root-bound phenomenon. When you do remove the burlap (remember, remove as much as possible without compromising the rootball), check the exposed roots for damage (i.e. ragged or frayed ends or broken or cracked roots). With a sharp set of pruning shears prune out the damage. Studies have shown that roots that have been handled this way callous over more quickly and new roots break closer to the cuts than unpruned damaged roots. As a matter of practice I always "treat" my pruning shears with isopropyl alcohol before and after I perform this operation on a plant. You don't want to transfer any disease pathogens from one root system to another.

When it comes to the actual placing of the tree or shrubs one often-overlooked procedure is proper "plumbing" the plant. After you have decided which "face" you want to feature (evergreens usually have a better side that you will want to show in one direction or another), lift or carefully roll the rootball onto the aforementioned pedestal of undisturbed earth. It is of paramount importance to "rattle" the ball as little as possible (remember: kid gloves!). Once placed and faced, stand back several yards and align the stem of the tree with something plumb, a house, or structure or utilize a plumb bob string to vertically align the plant. Walk around to a spot 90 degrees from your first spot and repeat this procedure. It's easier if you have an assistant help you adjust the rootball so you don't have to walk back and forth from the tree to repeatedly plumb and correct. Fill enough soil in the bottom of the hole to stabilize the plant. Shade trees that have not been properly plumbed will develop a "crook" in their trunks, as the central leader will automatically correct your oversight by growing plumb.

Brad Roeller
Manager of the IES Display Gardens

Week of 21 February 2000

Last week we ended our discussion of tree planting techniques with the placing and plumbing of the tree in the planting hole and the addition of enough soil into the bottom of the hole to stabilize the tree.

The preferred method of backfilling the planting hole is to "puddle-in" the soil. The "traditional" way of planting was to add a few inches of backfill soil into the hole and firmly "stomp" into place to achieve both stability of the rootball and a guarantee that there were no air pockets around the root zone. This was repeated until the hole was filled to grade. This is not recommended, however, as the force of the "stomping" destroys the fragile soil aggregate structure and largely eliminates the all-important macro-pores within the aggregate. A soil profile without a uniform aggregate and lack of pore space will not offer a conducive medium for new roots to grown into. I like to fill the planting hole about half full with the backfill soil. I then run a hose with a gentle stream of water into the hole. This may run for several minutes depending upon the size of the planting hole and the composition of the soil. Adjust the stream of water so as not to spill over the top of the planting hole. I wait until all the air pockets have "bubbled-up" to guarantee that the water has reached the bottom of the hole and all air pockets have been eliminated. Wait for the standing water to drain through the backfill soil completely. Add the remaining soil to within a few inches of the top of the hole and repeat the "puddling-in" operation. Do not manipulate the wet soil with tools or hands. To finish the planting operation form the "watering saucer" around the perimeter of the planting hole. This is nothing more than an earth berm 3 to 4 inches in height that will facilitate future watering by directing the water around and down through the original planting hole. Add the remaining few inches of soil to bring the finished grade to its proper elevation (i.e. flush or slightly below the all-important root flare of the tree) and soak with water.

Finally, add 2 to 4 inches of mulch over the planting hole to retain the moisture and to moderate the soil temperature throughout the growing season. It is imperative that the mulch does not contact the bark of the tree. There should be an inch or two space of bare earth contiguous to the stem of the tree. Mulch in contact with bark leads to rot which in turn creates a convenient avenue for insect and/or diseases to enter the plant.

Any mulch will work. I like to use pine or spruce bark or wood chips that have finished their active composting. Anything more than a 4-inch depth will probably impede root growth due to the fact that there would be too much cover over the root system thus limiting the amount of oxygen reaching the roots. Much more on the benefits of mulch in upcoming "Highlights".

Next week we'll finish our discussion on planting (hooray!).

Brad Roeller
Manager of the IES Display Gardens

Week of 28 February 2000

Winding down our discussion on planting techniques (finally), I'll lend some advice on the "finishing touches" of tree planting.

After the mulch has been spread, a decision has to be made as to whether the tree needs to be staked or guyed to withstand winds that may lead to blowovers. Past accepted practices called for routinely staking or guying (a practice done with large trees only) trees as part of the planting process. I still see this performed routinely, especially in large tree planting contracts. I will stake or guy a tree only when absolutely necessary: only if the rootball integrity was compromised in the transporting or planting process and the trunk of the tree is loose and in need of support will I stake or guy.

Recent testing at Rutgers and Morton Arboretum has shown that staking and guying, even if correctly done, leads to weak wood at the point of support. It is essential for proper cellular growth for trunks to move. The less movement of the stem the greater the amount of cellular distortion and subsequent weak wood. Trees that are staked too tightly, allowing for minimal or no stem movement, or trees that have been staked or guyed for a long duration of time, will not withstand typical wind shears and will invariably break at the point where they were staked. Three lessons to be learned, then:

• Stake or guy only if necessary.
• The support should allow for unrestricted stem movement.
• Remove the staking after one complete growing season, two maximum.

If I do stake a tree, the tension around the stem should allow movement of the stem at least an inch or two with minimal effort. This will support the trunk from blowing over in high winds while allowing essential stem movement.

I like to use two stakes (I prefer substantial wooden stakes as opposed to iron stakes) centered on either side of the stem. The distance from the stem to the stakes is typically the "drip-edge" of the branching. If the tree is placed where the prevailing winds will subject the tree to a stress in one direction, place your stakes accordingly (i.e. into the wind). If I determine that the tree needs to be staked, I will plan for this when I dig the planting hole, setting the stakes into undisturbed firm ground while digging. I "cant" the stakes a few degrees off plumb away from the stem to further enhance the support. The height that you place the supports (i.e. the wire and hoses that wrap around the stem) is typically just below the first scaffold (main) branches on the trunk. The diameter of the stem and height of the tree will determine the size wire I use for wrapping. I generally use 10 to 12 gauge wire for 6 in. diameter trees; 14 to 16 gauge for 2 to 4 in. diameter; and heavy duty plastic tape (similar to surveyor's flagging) for 1 in. caliper or less. Use only heavy-duty rubber (not plastic) hose to wrap around the stem. Cut enough hose to fully encircle the stem. (If you are supporting small trees with plastic tape, hose is not needed.) Run the wire through the hose and around the stake where you will connect the ends with pliers. Use a wire staple on the backside of the stake to attach the wire at the proper height. In the middle of the loop of wire, insert your pliers with one strand of wire on the top of the pliers and the other on the bottom. Twist your pliers in a circular motion tightening the wires by "braiding" them together. It is important to twist only enough to achieve the correct tension. Repeat this process directly opposite from the first hose. The supports should be "in-line" with the stem. Do not try to straighten a trunk to make it plumb by staking or guying; this should have been accomplished in the planting process.

Brad Roeller
Manager of the IES Display Gardens

Week of 6 March 2000

The last three areas to cover concerning tree planting are pruning at planting time, watering, and wrapping the trunk.

The conventional wisdom about pruning at planting time was to remove about 1/3 of the top growth of a tree or shrub at planting time to compensate for the loss of roots during the digging process. Sounds reasonable, but new research has shown that this is definitely not a good practice. Stored in the apical meristematic tissue of the growing buds in trees and shrubs is an auxin that triggers root growth. Overpruning at planting time is self-defeating as you are reducing the amount of this all-important growth auxin at a critical time in the establishment of the tree or shrub. Consequently, the only advisable pruning is to cut out broken or diseased wood. I delay what I term the "structural" pruning until the following growing season, once the root system is established and vigorous. Structural pruning is selecting the major "scaffold" branching of the tree that will determine the ultimate branching arrangement and structural integrity of the tree. (More on tree pruning in upcoming "Highlights"). Make sure that if pruning is required that you use sharp shears or pruning saws that have been sprayed or wiped with isopropyl alcohol to insure that any pathogens that are on your pruning tools are destroyed or you don't transfer any pathogens from the new tree or shrub to other plants in your landscape.

Wrapping. Young shade trees that come out of the nursery often suffer when put into an open environment in your landscape. Trees that have been reared in nursery rows where the young bark has been protected by the shade cast from neighboring trees may be subjected to "sun scald" in open environments. Nurseries often put a red or blue spot of paint on the south or exposed side of their trees so landscapers can plant the tree in the same exposure. The idea is that the bark on that side of the tree can withstand the "scalding" of the sun better than other sides of the bark. If I plant a tree in an open, exposed spot, I'll wrap the trunk up to the first main branch with asphalt-impregnated paper for protection. It is important to remove this wrapping after one growing season. Only thin barked trees like fruit trees and maples need to be wrapped. Older trees or rough-barked trees possess a texture that will dissipate the sun's heat better smooth-barked young trees. I also wrap fall-planted, thin and smooth-barked trees to protect them against frost cracking in late winter. Again, this practice is a one-time procedure and the wrapping is removed in the spring.

Watering. The most common reason for tree or shrub failure in the landscape is overwatering and/or underwatering. The goal is to keep the newly planted tree evenly moist, not saturated, while the new roots are forming and the plant is transpiring. Saturated ground will actually starve the plant of oxygen, which is essential in root formation. Dry earth will likewise not support growth. If you have mulched the plant well at planting time, and if your soil has good moisture-retaining properties (i.e., an above average amount of clay and/or organic matter), you may not have to water for weeks at a time. The key is to monitor the soil moisture frequently (several times a week, depending on rainfall). Don't just feel the mulch; push it aside and probe with a thin, sharp metal rod or bamboo stake down into the root zone to determine if watering is warranted. The condition of the top inch may be far different than that where the roots are developing. When you do water, water thoroughly.

Brad Roeller
Manager of the IES Display Gardens

Week of 13 March 2000

Has spring arrived? I've spotted my first robin; male turkeys are gobbling up a storm, snowdrops (Galanthus nivalis) and winter aconite (Eranthis hyemalis) are in their full glory. Is it my imagination or are the red maples buds swelling and taking on that redder color? One can only hope! I know I'm ready for spring and itching to start gardening! There are several tasks that are best accomplished during the next few weeks. Timing is all-important in spring, as opportunities are quickly lost as the spring season marches on.

Lawns. With the nice drying winds on recent days, the top few inches of topsoil have dried enough to permit starting the job of thatching your lawn. Stay off wet or saturated turf, as it will lead to soil compaction. I try to avoid running heavy equipment such as garden tractors on my lawns until they are thoroughly dry. How to thatch. Well, if your lawn is a large one, you might want to rent a power rake from your local rental center. I like to use my old, reliable bamboo rake and hand-rake out the dead grass (thatch). This action seems to stimulate growth and hasten the "green-up" of lawns. I usually take a break from raking to check the pH of the top few inches in several locations throughout my lawn. I use a pH meter which I consider an essential gardening tool. You can bring a sample to have it tested at your local Cooperative Extension. Most grasses flourish in an environment with an acidity range of 6.8 to 7.2. If the soil is too acidic, apply limestone to correct. Late fall or early winter is the best time to correct the pH as the change in acidity often takes months to accomplish. Early spring (now) is also an opportune time to perform this task. If your soil is too alkaline, apply elemental sulfur to lower the pH. Generally, this is done for pHs over 8.0, and is a pretty rare occurrence in our area. The following table provides some guidelines for adding lime to adjust the pH:

Note: all the amounts are lb/1000 sq. ft.

Example: If a pH test indicated that your pH was 6.0 and you had a loam type aggregate, you would spread limestone at a rate of 40 pounds per 1000 square feet of turf to bring the pH to an optimum condition for the grass.

I like to use the pelletized limestone broadcast with a "cyclone-type" spreader.

It is too early to establish new lawns or renovate existing lawns. April or early May is the time for that. Likewise it is too early to fertilize lawns. Interestingly, new research is showing that little is accomplished by applying fertilizer in spring, despite what the commercials tell you!

The important fertilization is the fall feeding, especially if you are using organic or controlled release fertilizers. (More on fertilization in upcoming "Highlights"). Now is a great time to add soil amendments such as granular humates to your topsoil. Humates are mined organic deposits (the actual mineral is Leonardite). The organic fraction of the soil, often called humus, is a product of the decomposing activities of microflora. Since it contains the organic carbon and nitrogen needed for microbial development, it is the dominant food reservoir in soils. By adding humates we are, in effect, "feeding" soil microbes, thus facilitating the conversion of nutrients and organic matter to more soluble forms that plants can use.

Brad Roeller
Manager of the IES Display Gardens

Week of 20 March 2000

Last week we talked about some of the lawn related tasks that are best done before growth starts in spring. This "Highlights" will point out some gardening tasks that are best accomplished during the late winter, early springtime.

It is still important to keep those evergreen boughs on your perennial beds for another month or so. As pointed out last fall when the boughs were laid on the garden beds, plants like a slow "cool-down" in the fall and a slow "warm-up" in the spring. I like to delay the rise in soil temperature as long as possible without impacting the top-growth of the perennials. This will protect the early spring-blooming plants from the inevitable late April- early May frosts. So, keep those boughs on even though the thermometer is currently teasing us.

I do like to cut back certain plants at this time of year. Ornamental grasses, especially Miscanthus, will start sending up new growing tips very early because of the protection afforded them by last season's foliage. If you wait to cut back your grasses until late April or May, you will also be cutting off several inches of new growth which will setback the plant considerably. Therefore, ornamental grasses are usually the first of the perennials which weren't cut back in the fall to be addressed in spring. Cut individual grasses uniformly to 1.5 to 2 inches above the soil surface. I like to use sharp, electric hedge shears, as some of our older maiden grasses are a foot or more in diameter making pruning shears almost useless. Importantly, these growing tips have been protected all winter by last season's growth that has now been removed. After cutting off the old stems, cover the crowns with a layer or two of freshly cut evergreen boughs for insulation.

It is still too early to cut back subshrubs such as Perovskia, Buddleia, Lavendula, andNepeta. These should be cut back to viable wood just at the onset of growth in spring. When I see honeysuckle start to leaf out and forsythia and Virginia bluebells start to bloom, I perform this garden task. Depending upon the severity of the winter and the amount of snow cover, the height that you cut back these plants will vary from year to year. This year should be a good one for minimal cutting back of these types of plants due to the early coming and generous depth of snowcover.

Finally, any leaves that have blown into your flowerbeds should be carefully raked out. Remember that the growing tips of bulbs and early spring perennials are just below the surface, so be careful. I also remove evergreen bough to cut off foliage that was left for winter interest and/or protection last fall. Remember to replace the boughs after this task is done. And, most importantly, stay off wet soil at all costs and look for and identify the location of your perennials before you enter the bed. Stepping on plant crowns is not a good practice! If you left last season's foliage in place, or cut back the foliage to a 3 to 4 inch height, finding your plants should not be a problem.

Brad Roeller
Manager of the IES Display Gardens

Week of 27 March 2000

On one of those wonderful spring-like days last week, I took the opportunity to eliminate a nasty pest from a few specimen shrubs around the Institute's Gifford House Visitor and Education Center. The pest is (was) the magnolia scale, Neolecanium cornuparvum. My choice of control was to use a "horticultural" oil that would suffocate the overwintering adults.

Horticultural oils have come a long way in the last 20 years. Prior to 1970, these oils were not as refined as they are today and as a result were mainly relegated to dormant season use due to their phytotoxic properties. Today, most of the popular oils are what are termed "superior" or "summer" oils. They are more refined than their older counterparts and can be used year round. If unsure of the quality of the oil, check the label. A superior oil should contain at least 92% unsulfonated residues and less than 8% sulfonated aromatics or residues. The less sulfonated residues, the better the grade of oil and less chance for phytotoxicity to the plants. Two popular and reliable superior oils are Sun Spray Ultra-Fine Oil and Volck Oil Spray. If I choose to use oil to control a pest, I'm now using superior oil exclusively, regardless of whether the application is dormant or verdant (in-leaf).

If the pest has reached a level that warrants intervention with a pesticide, oil is a good "natural" pesticide as it degrades relatively quickly and is only slightly toxic to humans and mammals. I like to spray early in the morning when there is little or no wind drift. Never spray oil when the temperature is below freezing or above 85°F. Never apply oils within one month before or after applying sulfur sprays (a natural fungicide). This time of year I monitor for the following pests: ccale on magnolias, azaleas, some evergreens (arborvitae and hemlock), and euonymus; mites on crabapples, arborvitae, some pines and hemlocks; and the earliest aphid I know of that causes that tell-tale leaf curling on many viburnums.

I mix a 3% solution for dormant season applications (½ cup of oil per gallon of water). I use a 2% solution when plants are in leaf (1/3 cup of oil per gallon of water). On plants that I know are sensitive to oil sprays, I reduce the oil down to 1% (2½ TBL. per gallon of water). Do not use horticultural oils on blue spruce or some white fir cultivars ("Candicans" or "Violaceae"), as the oil will remove the bluish color from the needles. I also avoid spraying drought-stressed or diseased plants with oil.

New developments in the "green industry" with innovative uses of oil have led to a new class of herbicides. By actually increasing the amount of phytotoxic impurities (those aforementioned sulfonated aromatics), the oil becomes more phytotoxic and actually dissolves the cuticle layer of the cell wall of the plant. This causes the cellular sap to "leak" out of the plant leading to death. There is new evidence that oils can have fungicidal properties. Although not currently labeled as a fungicide, oil will coat the leaf surface making it difficult for fungal spores to fruit and penetrate the leaf surface. Organic growers are using natural vegetable oils such as cottonseed or canola oil instead of petroleum-based oils. These products can be used on vegetables right up until the day of harvest.

Brad Roeller
Manager of the IES Display Gardens

Week of 3 April 2000

After a long, hard winter we're all itching to get out with our brand-spanking new Felco pruning shears and super-sharp pruning saws and cut away! Although this is an excellent time of year to perform certain types of pruning, you should be aware that the number two reason for tree death is improper pruning (right behind construction-related damage). So before those shears beckon, a few principles should be followed.

First of all, while you don't have to be an arborist to prune trees or shrubs properly, novices should take advantage of the numerous books and pamphlets available to aid them in their decision making. Two excellent references are Pruning: An Illustrated Guide to Pruning Ornamental Trees and Shrubs, a Cornell Cooperative Extension pamphlet (information bulletin 23) available for about $5; and Pruning Simplified by Lewis Hill copyright 1986 by Storey Communications, Inc. (ISBN 0-88266-417-4). Both of these references are extremely helpful to the beginner.

Importantly, differing "classes" of woody plants are pruned differently. Pruning deciduous trees is quite different than pruning evergreen trees. Likewise, pruning established landscape trees should be approached far different