Posted on Saturday, May 08, 2010 by admin in Garden Tips |

Each year, the Pennsylvania Horticulture Society, recognizes little-known and under-used woody ornamental plants of exceptional merit and promotes their use by granting them Gold Medal Awards. Since 1988 when the program began, Gold Medal Awards have been received by 46 plants. All of the previous year’s, as well as this year’s winners, are superb garden plants that have been selected for insect and disease resistance as well as minimum maintenance. This year’s winners include:

Aesculus pavia

Aesculus pavia the red buckeye, is a native horse chestnut that can be grown as a very large shrub or small tree. The red buckeye spends its youth as a bit of an ugly duckling, having an ungainly growth for its first 5 to 8 years. But it, like the swan, matures into a graceful, rounded to spreading, almost symmetrical, 20-foot-tall by 20-foot-wide adult under cultivation and a 35-foot-tall by 35-foot-wide adult in the wild. The red buckeye prefers a loamy well-drained soil and does well in a full sun to edge of the forest sun exposure.

The flowers are particularly attractive to hummingbirds. The fruit is the usual shiny brown nut contained in a smooth tan capsule. Aesculus pavia is hardy from zones 6A to 9A.
Halesia dipera magniflora

Halesia dipera magniflora, the large-flowered Florida silverbell, is a medium-sized shade tree whose bloom rivals that of the flowering cherries. It is native to the Florida panhandle, but survives well into zones 6 and even 5 sheltered sites. The foliage is a clear dark green. The tree is apparently insect and disease free, lives up to 75 years, and grows to 50- feet- tall at maturity. The large-flowered Florida silverbell begins flowering as early as 3 to 4 years after germination.

The flowers are profuse, bell-like, borne in clusters of 2 to 4 blooms at the nodes of last year’s growth, white, showy, and are up to 2 times the size of the flowers borne on H. carolina and H. monticola. The tree blooms toward the end of May in the Baltimore area. The flowers are followed by groups of two-winged fruit that persist well into the winter.

Heptacodium miconiodes

Heptacodium miconiodes, the seven son flower, is a rapid-growing native of China that can be grown as a tall, arching, multi-stemmed, 6-to-10-foot-tall shrub or as a 15-to-20-foot-tall single stemmed tree. It tolerates a wide-range of growing conditions, wet or dry or acid or alkaline soils; shade to full sun, where it remains compact and blooms most profusely; is hardy to zone 4, and can probably be killed only with a concentrated effort.

The foliage of the seven son flower breaks bud early in the spring; matures to a strikingly-textured, handsome, dark green; and the yellow fall foliage is retained for a long time. As the leaves fall, the striking, light tan, paper-like, exfoliating bark is revealed to provide interest for the winter.

The small, creamy-white, honeysuckle-like blossoms are born in mid-August to the end of September in clusters of seven, hence the name seven son flower in its native China. The calyces of the blossoms are retained, continuing to grow, turning a reddish hue and subtending the rosy-colored fruit that becomes a rich purple in color before fading along with the fruit, into a tan obscurity after a several-weeks-long display.
Ilex verticillata `Winter Red’

Ilex verticillata `Winter Red’ is the `standard’ by which all other winterberries are judged. It is a tough plant that performs best in full sun but will thrive in full shade, where it literally glows with its surprisingly glistening deep red berries. In full sun, the berries may be borne so profusely that they obscure the stems that hold them. `Winter Red’ begins to fruit as early as one to two years of age. Birds do not eat the berries until early spring, when other trees and shrubs are stripped of their obviously more palatable fruit.

The foliage, which is an unobtrusive green, is best used as a backdrop for other plants `Winter Red’ will eventually become a 10 to 12 foot tall, multi-stemmed, suckering shrub. The older branches must be periodically cut to ground level to stimulate the development of new stems to guarantee a good fruit display.

`Winter Red’ is free of insect and disease problems. Because it is a dioecious plant, having only male or female flowers on any given plant, it is necessary to provide a male pollinator in order to enjoy fruit. “Winter Red” is hardy to zone 4.

Russell Balge, Regional Specialist, Western Maryland Research and Education Center, University of MD, Cooperative Extension Service