What Grows There :: Hugh Conlon, Horticulturalist, Garden Advisor, and Photographer

December Garden Classic – Prague Viburnum

Posted by Hugh on December 7th, 2010

Garden Classics: a monthly retrospective featuring a singular plant species either under-planted or relatively unknown to gardeners living in the Southern Appalachian Region.

Prague Viburnum in early May

Prague viburnum (Viburnum x pragense) is a lovely evergreen shrub, which combines all the best traits of its parents (V. rhytidophyllum and V. utile). It is winter hardy throughout the Southern Appalachian region (USDA zones 6 and 7). As the name indicates, this hybrid viburnum hails from the Czech Republic. It grows rapidly to a mature height and spread of 8 – 10 feet.

The rose pink colored floral buds begin to open in early May and lightly fragrant, creamy white flowers bloom for 2-3 weeks. Its lustrous dark evergreen foliage is comprised of 2 – 4 inch elliptical shape leaves. Prague viburnum is a teriffic stand alone specimen shrub or you may group several as a hedge or privacy screen. It serves as an effective foil against peering or noisy neighbors when planted in one or more rows 6 – 8 foot apart.

Plant in any moderately drained garden soil and in a full sun to partial shade exposure. Disease and insect pests seem to leave this viburnum alone. Moderate resistance to deer feeding is reported, perhaps useless information if the deer are hungry.

Rarely do I pruned my 15- year old Prague viburnum, only when it attempts to crowd out a nearby shrub in my admittedly overplanted garden.

Choosing a Cut Christmas Tree

Posted by Hugh on November 30th, 2010

: Christmas Trees at Local Garden Center

Fire safety in the home should be your primary concern when purchasing a freshly cut Christmas tree. There are numerous “choose and cut” Christmas tree growers in the Southern Appalachian region (USDA zones 6 and 7). Trees are harvested by the tens of thousands in the mountainous locales and are shipped nationally and internationally. You can also purchase a tree from a large chain store or a local tree lot.

The evergreen species with best needle retention include: fraser fir, douglas fir, and balsam (Canaan) fir, followed by white pine and Scotch pine. Norway spruce rates the poorest in needle retention. Canadian or the western U. S. growers ship Balsam fir and Douglas fir trees into the region in time for post Thanksgiving sales. These trees are harvested 4 – 6 weeks ahead because of shipping and weather concerns.

When shopping at a tree lot, shake or bounce the tree to check needle retention. Needles should be soft and fragrant.

Re-cut the base (butt) of the tree, removing at least 1 inch prior to setting it into a stand indoors. Secure the tree and fill the water reservoir. Inspect the reservoir daily for water uptake. A freshly cut 6-7 foot tree may consume a 1/2 pint (8 oz.) or more of liquid per day.

“It’s Wort…not Wart”

Posted by Hugh on November 25th, 2010

Barrenworts (Epimedium spp.) are a collection of ground cover species mostly from Asia and Europe. None are native to North America, but most thrive in gardens in the Southern Appalachian region (USDA zones 6 and 7). There are currently 21 known species worldwide.

Also called Bishop’s hat, barrenworts are one of our finest groundcovers for part sun to part shade areas. Some are evergreen or others deciduous with leaves gradually turning red, purple, crimson and scarlet in late fall. Most species grow 6-12 inches in height.

The dictionary defines the word “wort” as “a herbaceous plant lacking a permanent woody stem” or “a flowering plants important as a medicinal herb”. Barrenworts are both. Barrenworts are woodland plants which are used as groundcovers woodland garden or shaded rock garden. Plants are slow growing at first and newer varieties are expensive to purchase.

A soil should be well amended with organic matter and kept moderately moist to speed fill-in. Once they become established, barrenworts are tough survivors in dry shady areas of the garden.

Whether you grow evergreen or deciduous types, cut them back (4 – 5 inches mowing height) to the ground in late winter to visibly enjoy the small white, yellow, pink or red flowers, depending on the species grown. Barrenworts are disease, insect and deer munching free.

Autumn’s Last Hurrah -Bradford Pear

Posted by Hugh on November 22nd, 2010

'Bradford' Callery Pear

Currently, the Southern Appalachian region (USDA zones 6 and 7) is enriched by the vibrant red fall foliage of callery (ornamental) pears (Pyrus calleryana), commonly identified as ‘Bradford’ pear. There are several cultivars of callery pears besides Bradford.

A great deal of negativity has befallen Bradford pear, some not totally deserved. Yes, Bradford is weak- wooded and self-destructs in 15-20 years. ‘Cleveland Select’, also called ‘Chanticleer’, possesses all the positive attributes of Bradford. Cleveland Select has an upright branching habit which is less prone to limb breakage. Both cultivars demonstrate above average fireblight disease resistance.

The white flowers of callery pears lead off the spring season, and their glossy dark green foliage follows shortly thereafter. As medium sized trees, most cultivars reach 35-40 feet in mature height and of varying widths. Trees are not fussy, growing in any well-drained soil. Two year old established trees exhibit exceptional drought tolerance. In many years, maroon or bronze red autumn foliage color is effective into early December.

Callery pears are native to China and Korea and may become invasive in woodland and roadside areas, their vigorous seedlings choking out the competing native vegetation.

Brighten Up a Drab Corner in Your Garden

Posted by Hugh on November 20th, 2010

Crippsii falsecypress (Chamaecyparis obtusa ‘Crippsii’) is one tall 20-25 foot high evergreen shrub (or small tree). Its lacy golden evergreen foliage catches your attention almost any season of the year. Unfortunately, Crippsii is rarely seen in landscapes because few landscape architects and designers know it or can not find it in the nursery trade.

Ten years ago a credit union near my home planted five around their 2-story building. today, each shrub grows slightly different due to varying sunlight exposures around the edifice. Shrubs receiving mostly full sun grow tighter, more compact, while those on the shadier north side display an open looser branching form.

Crippsii prefers a moist, well-drained, and organically rich soil. Newly planted shrubs are best sheltered from drying winter winds and irrigated during summer dry spells. As plants adapt to their surroundings, Crippsii handles seasonal cold, heat and drought extremely well.

Crippsii grows well here in the Southern Appalachian region (USDA zones 6 and 7). Disease and insect pests are rarely seen, although numbers of Crippsii currently planted are small. Bagworms may potentially become an occasional pest in years when larval populations are high.

Trident Maple Has 4- Seasons Interest

Posted by Hugh on November 18th, 2010

Over the past decade residential lot sizes have shrunken. Small and medium sized shade trees are a better choice over large traditional choices of red and sugar maples. Trident maple (Acer buergerianum) is our best mid-sized summer shade maple in the Southern Appalachian region (USDA zones 6 and 7).

By mid-November trident has shed its gorgeous reddish purple autumn foliage. The tree’s semi-upright framework and textural bark are wonderful winter features. The outer dark brown bark chips off, revealing the lighter colored sapwood within.

Trident maple thrives under full sun in moist, well-drained soils. It struggles in heavy clay soils. Dirr[i] reports that trident is tolerant of moderately alkaline pH soils. After two years planted, an established trident tolerates summer dry spells and urban air pollutants better than most maple species. Wood strength is on par with red maple. Purchase a well-branched central leader tree.

This native of Japan produces very few seedlings. The lustrous three lobed leaves appear in mid-April, followed by numerous inconspicuous pale yellow flowers a week or two later. In September smallish two-winged (samara) seeds begin to whirligig down.

Trident maple is also an excellent choice as a street tree, particularly under power lines. Aeryn® is a leading cultivar which matures into a 35-40 foot high and 25-30 feet wide tree.

[i] Dirr, Michael A. 2010. Manual of Woody Landscape Plants (6^th Ed.). Stipes. Champaign, IL.

Doghobble for Shady Landscape Areas

Posted by Hugh on November 11th, 2010

Drooping doghobble or fetterbush (Leucothoe fontanesiana) is native to woodland areas in the Southern Appalachian region (USDA zones 6 and 7). Doghobble is a tall ground cover, averaging 3 – 4 feet in height. The long gently arching evergreen branches display a rambling nature, best reined in with hand pruning as needed.

White fragrant flowers, mostly hidden beneath the foliage, lightly scents the May garden for 2-3 weeks. From late fall into winter, individual branches may bronze and, in extreme cases, turn deep purple. By spring most branches have regained their lustrous dark green color.

Doghobble grows alongside rhododendrons, pieris, azaleas and hollies, all which prefer acidic, well-drained, and organically rich soil. It displays only moderate heat and drought tolerances and should be irrigated when seasonal moisture levels fall below normal. Too frequent irrigation may also trigger the onset of foliar diseases.

Doghobble is dominant under dappled or partial shade and grows sparingly under deep shade. Doghobble is a good choice planted under large shade trees, areas previously set with low, ground hugging junipers or perennial ground covers. Over the years the shade trees cast more shade, and the sun-loving perennials and junipers thinned or died out.

Striped Maple For The Shade Garden

Posted by Hugh on November 8th, 2010

This past weekend, while walking in the Smokies Mountains on a rather brisk rainy autumn day, the bright yellow autumn foliage color of striped maple (Acer pensylvanicum) caught my attention. Also called “moosewood”, it is the only snake-bark maple native to the U.S. The greenish bark is marked with dark vertical lines or “stripes”.

The reason that we don’t see this wonderful small maple in our gardens is that it prefers a cool moist woodland environment and does not survive in hot urban habitats. Striped maple grows 15-20 feet in height as a small tree or a multi-stemmed shrub. Leaves are 3-lobed with very small teeth along the leaf margin.

It may be confused with Mountain maple (A. spicatum), also with a 3-lobed leaf, but with coarser teeth along the leaf margin. Both species may grow side by side in the Southern Appalachian region (USDA zones 6 and 7). This is the southern growing range for striped maple.

Long 4 – 6 inch raceme flowers open in May, yellowish green. Many double-winged seeds (botanists call them “samaras”, kids refer to them as “helicopters”)) may form along the raceme and are ripe by late September for dispersal.

Be Careful What You’re Cutting Back

Posted by Hugh on November 4th, 2010

Halfway through the autumn season, new plants have come to life, while most are retiring for a long winter’s nap (dormancy). About 4-5 weeks back, the leafy growth (vegetative) stage of the surprise lily (Lycoris radiata), also called “resurrection lily or “naked ladies”, appeared (left and center photos). When last seen in late July and August, brightly colored stalks of lycoris flowers had popped through with no leaves present. The floral stalks have since withered and disappeared.

The strap- shaped lycoris leaves emerged for their photosynthetic stage, to build or renew food storage reserves in their roots. Cutting or mowing off the foliage would be detrimental to the promise of flowering next summer.

New leafy foliage of Italian arum (Arum italicum ‘Pictum’) (right photo) has also arisen. Its new bright green metallic arrowhead shaped foliage is poking through the fallen leaves which litter the shade garden. Its glossy green arum foliage arrives for the winter and spring seasons to form an evergreen ground cover.

Both lycoris and Italian arum are examples of long-lived perennials which thrive in a richly composed, well-drained soil. Container grown plants may be planted anytime that the soil can be worked up.

Hardy Camellias Re-Awaken the Autumn Season

Posted by Hugh on November 1st, 2010

‘Winter Star’ camellia (pale pink- photo on left) is the first camellia to bloom in the Conlon garden this fall season. My 8 year-old camellia has 50 or more flowers currently opened and promises to continue blooming through most of November. Other hardy fall blooming cultivars are heavily budded and will open thru mid- December, weather permitting.

A few days later the cultivar ‘Cleopatra’ (rose pink- photo on right) opens and it has bloomed reliably during its 8 year tenure. Camellia experts rate ‘Cleopatra’ as not reliably flower bud hardy below – 5° F. Open camellia flowers are more susceptible to an evening cold snap than tightly closed buds.

Camellia culture is similar to azaleas and rhododendrons. Plant them in half day sunlight (morning exposure preferred) and in an acidic, well-drained soil which has been generously amended with organic matter. Camellias are susceptible to very few disease and insect pests. Irrigate newly planted camellias weekly during extremely dry summer periods and protect them against the harsh winter winds.

Prune most camellias when the spring flowering period is over in late April -early May and before the spring growth flush has begun. This includes the fall bloomers. Primarily prune shrubs to limit their height / spread and to remove dead / damaged branches.