Horticulture: Extension: Gold Medal Plants

1999 Gold Medal Winners

Take Home a Georgia Gold Medal Plant...
And Take Home a Winner!

By Gary L. Wade
Georgia Extension Service

Shopping for new landscape plants this spring? Check out the 1999 Georgia Gold Medal Winners.

Since 1994 the Georgia Plant Selections Committee, Inc., has been helping gardeners throughout Georgia improve their landscapes by offering a recommended list of superior landscape plants.

Made up of professionals from Georgia's Environmental Horticulture industry, including nurserymen, flower growers, landscapers, landscape designers and garden center managers as well as University of Georgia faculty in Horticulture, the Georgia Plant Selections Committee was organized in 1994 to promote the production, sale and use of superior ornamental plants.

Without the help of a professional, it's easy to get stuck with a lemon. One that looks great in a pot but becomes a high maintenance nightmare in the landscape. That's where the Georgia Plant Selections Committee comes in.

Each year the Committee selects an annual flower, a herbaceous perennial, a shrub and a tree from a long list of nominees and awards them a Georgia Gold Medal for superior performance. Only the best of best can earn the top honors. The committee considers seasonal interest, outstanding or unusual qualities, ease of propagation, hardiness, adaptability, durability and pest tolerance.

The 1999 Georgia Gold Medal Winners are Nova Pentas, an annual that attracts butterflies and hummingbirds like magnets and blooms from spring until first fall frost; Lenten Rose, an old garden favorite pass along plant that makes a great low-maintenance ground cover in dry shady sites; Mohawk Viburnum, a fragrant flowering shrub that bathes the spring landscape in perfume delight, and American Yellowwood, a native tree bearing spectacular white wisteria-like clusters of flowers that cascade downward like summer rain.

Look for these and other Georgia Gold Medal Winners in the Garden Center this spring. They are the blue bloods of the nursery industry and sure to be proven performers in your landscape.

Drawings by Karen Saul Smith

Plant pentas (Pentas lanceolata) in your summer landscape, and swarms of butterflies and flocks of hummingbirds will suddenly appear.

Also called "Egyptian starflowers," pentas are quickly becoming one of the most popular summer bedding plants in the Southeast. Part of the reason is that they're native to tropical Arabia and east Africa. They thrive in hot, humid summers like Georgia's.

Pentas are available in a variety of colors, from red to white, lavender and pink. However, the Georgia Plant Selections Committee singled out one variety, 'Nova,' as superior.

"It's a great garden plant," says Dottie Myers, Atlanta landscape architect and committee member. "It starts blooming early and blooms all summer, forming clusters of rose-pink flowers 3 to 4 inches across."

A single plant may have 10 to 15 flower clusters at one time, each with 10 to 30 florets.

The rose-pink blooms of combine particularly well with the deep purple of Salvia guaranitica, the blue of Scaevola aemula 'New Blue Wonder,' the gray of Artemesia 'Powis Castle' or the magenta of crimson fountain grass.

The thick, 18-inch, erect stems hold up well when cut and used in summer flower arrangements.

Some pentas are slow-growing and are susceptible to root diseases, but not Nova. The plants are vigorous from Savannah to Hiawassee, from Dalton to Bainbridge. Even during wet periods, Nova pentas continues to grow and flower without major disease problems.

Pentas prefer warm soils. So it's best to plant them after April 15 in south Georgia and after May 1 in the northern half of the state. If you plant too early, you will be disappointed, because they stall out and stop blooming.

Pentas prefer a full-sun site and good drainage. A raised bed enriched with organic matter will help them thrive. The plants grow about 15 inches wide and 2½ feet tall, so plant them 1 foot apart.

As with many annuals, pinching new growth lightly early in the growing season will promote branching and more flowering stems.

Pinch out 1 to 3 inches of the terminal two to three times between May 1 and June 15. This will result in a bushy plant covered with flowers by the Fourth of July.

Apply 1 pound of 10-10-10 per 100 square feet at planting and at six-week intervals all season. Water as necessary when rainfall is limited, but don't keep the plants too wet.

Occasional deadheading (removal of old blossoms) all season will help keep the plants vigorous.

Nova pentas can be propagated from cuttings. It roots readily, like coleus, when placed in well-drained potting soil and kept moist. Cuttings can also be taken in late fall to maintain plants over the winter for spring planting.

Nova pentas should be readily available as a potted plant or in flats in 1999. Several growers throughout the state are producing it.

Like a previous Georgia Gold Medal Winner, New Gold lantana, Nova pentas takes its place in the winner's circle as a durable, nonstop bedding plant.

It's sure to please gardeners and landscapers looking for an alternative to marigolds and zinnias in the summer landscape.

Lenten rose (Helleborus orientalis) is a "tough as nails" perennial plant Georgia gardeners have quietly loved for more than 100 years. It never got much fanfare but was always welcome as a gift or pass-along plant.

Sometimes called Christmas rose, Lenten rose heralds spring. It blooms in midwinter and bounces back consistently each year regardless of the previous season's hardships.

Because it blooms during the cold of the year, the flowering may last eight to 10 weeks.

It's one of those plants that seems to fade into the green background for most of the year. Then it becomes the center of attention in late winter.

Its blooms are white, pink, plum, green, magenta and many pastel shades in between. Cup-shaped flowers rise above the foliage. Like bells, they bend downward at the ends of 12- to 18-inch stems.

Once the flowers fade, the foliage seems to darken, providing a glossy, evergreen ground cover year-round. Individual leaves may be 15 inches across, with seven to nine leaflets spreading from a central point like spokes on a wheel.

Lenten rose isn't a true rose. It's a member of the Ranunculus family. Of about 20 species, only two are commonly sold in the U.S. nursery trade.

Flowering is only one of Lenten rose's merits. It makes a durable ground cover in dry, shady places and under trees where few other plants will grow.

A native of Greece and Asia Minor, Lenten rose is hardy in zones 4-9. It's a slow-growing perennial and may require several years to fill in and form a solid ground cover. But it's well worth the wait.

Lenten rose is best transplanted in fall. Most garden centers sell it as two-year-old container plants. You can also transplant young seedlings from established plantings or divide large, mature plants.

When transplanting, work a little organic matter into the planting area to help establishment and growth. But don't do any serious tilling if you plant under large trees.

Seed propagation is extremely slow and difficult. It takes two or more years to get a plant ready for the garden. Seed propagation also results genetically in a variety of flower colors that may differ from that of the parent plant.

Water and a little fertilizer applied regularly through the first growing season is critical to successful establishment. Light applications of a 10-10-10 each two months during the first season will get the plants off to a good start.

Once they're established, water during dry periods, and lightly sprinkle 10-10-10 in October and March. Be sure to water it in.

Cut back leaves damaged by storms or ragged from age in early January before blooming. The foliage will regrow quickly in spring, after the flowers have faded.

Lenten rose reseeds freely once established. So in a few years, you'll have lots of young plants to pass along to friends and neighbors. It truly is a gift that keeps on giving and a sure winner as a low-maintenance, trouble-free ground cover.

Plant some Lenten rose this spring and discover the award-winning qualities this 1999 Georgia Gold Medal selection has to offer.

(Paul Thomas and Gary Wade are Extension Service horticulturists with the University of Georgia College of Agricultural and Environmental Sciences.)

If fragrance is your fancy, add Mohawk viburnum to your landscape. It's one of the most aromatic shrubs in the landscape, filling the early spring air with its spicy, clove-like fragrance during bloom.

It's also an early bloomer, flowering from mid to late March in north Georgia and even earlier farther south. It bears flowers in clusters 3 to 4 inches across before the leaves appear.

The flowers are bright red in bud and open to white with just a blush of pink. The buds begin to show color several days before the flowers open. So the color display lasts seven to 10 days.

Mohawk viburnum was developed by the U.S. National Arboretum's Plant Introduction Program and released in 1953. It's a hybrid cross. It combines the durability and adaptability of Burkwood (Viburnum x burkwoodii) with the fragrant flowers of Koreanspice (Viburnum carlesii) .

Since it's deciduous and loses its leaves in winter, Mohawk viburnum is a great shrub for a mixed border with evergreen shrubs, where it can fade into the background in winter.

It's a medium-sized shrub, reaching 7 to 8 feet high with an equal spread. Use it behind low-growing evergreens, like dwarf yaupon holly or Sargent's juniper, and in front of tall evergreens like burford holly, lusterleaf holly or Little Gem magnolia.

A grouping of three to five plants will provide the most dramatic effect in the landscape. With a little effort and creativity, you can also train the plant as an espalier along a wall or fence.

Leaves 2 to 4 inches long emerge soon after flowering and become glossy green on top and light-gray underneath. Insect pests and diseases don't bother the foliage. Fall color ranges from bright orange to wine red, depending on weather conditions.

Mohawk viburnum is hardy from zones 5-8, making it a fine landscape plant for all of Georgia. It grows best in full sun to partial shade and moist, well-drained soils.

Prune conservatively to encourage branching, yet maintain a natural form.

Fertilize in early spring with a 16-4-8 or similar fertilizer. Broadcast it evenly over the soil surface near the drip line or tips of the canopy.

For a landscape bathed in fragrance, combine Mohawk viburnum with other fragrant plants. Good choices are winter honeysuckle, which blooms in January; winter daphne, which blooms in February; and fragrant tea olive, which blooms in October. Then open the windows and enjoy the heavenly sweet perfume of Mother Nature.

Fragrant flowers, pest-free foliage, outstanding fall color and interesting, pale gray bark put American yellowwood (Cladrastis kentuckea) in the winner's circle in 1999.

A native tree that gets its name from the color of its heartwood, American yellowwood can be found growing in fertile upland sites, limestone ridges and cliffs of Georgia, North Carolina, Tennessee, Alabama, Missouri, Arkansas and Oklahoma.

It's a medium-sized tree, reaching 30 to 50 feet tall at maturity. That makes it an excellent specimen for today's urban landscapes.

The tree looks best when trained to grow as it does in the wild, with low-growing branches. It develops a broad, rounded crown with delicate-looking, but surprisingly strong, branches. It's hardy in zones 4-8 and will grow well throughout Georgia.

If the tree has a fault, it's that it may take five to eight years to come into bloom. But it's well worth the wait.

Flowering is a sight to behold in late April and early May. Fragrant panicles of white flowers, 8 to 14 inches long, cascade from the ends of branches.

The tree is also noted to be an alternate bloomer, flowering heavily one year, then resting the next.

Soon after flowering, the tree develops brown pods 3 to 4 inches long. Each contains five hard, flat seeds. The seeds have hard coats but will germinate if scraped with a file or sandpaper before planting. Soaking them in warm water for 24 hours can also help germination.

The tree is hard to propagate from cuttings. It has been commercially propagated exclusively from seed.

The leaves are compound, with seven to eight leaflets alternating along each stem. They are rich green in summer, turning soft yellow in fall.

As the fall leaves shed, the tree provides a strong winter accent with its pale gray, smooth trunk and sinewy branches. Add night lighting, and the tree makes a dramatic statement in the winter landscape.

American yellowwood grows best in full sun to partial shade and well-drained soils. It may sit idle for a year or two until is firmly established, but 1 to 2 feet of new growth is common on healthy trees.

Go easy with fertilizer, particularly during the first two years. Then apply 16-4-8 fertilizer uniformly at the drip line or edge of the canopy once or twice each year.

Yellowwood prefers a pH around 6.5. It may need occasional liming in acidic soils. Get a soil analysis through your county Extension office to determine the need for lime.

Pruning is best done after the tree leafs out, since it tends to bleed excessively when pruned during the winter. Some pruning will be necessary, particularly when the tree is young, to encourage well-spaced branches and prevent narrow crotches that may weaken with age.

Few insects and diseases bother American yellowwood if you maintain it properly. Once established, the tree grows a deep tap-root system. It's very drought-tolerant, making it an excellent choice for low-water-use sites.

American yellowwood should be readily available in Georgia garden centers and nurseries in 1999. Try it and see for yourself the tree's award-winning qualities.

(James Midcap and Gary Wade are Extension Service horticulturists with the University of Georgia College of Agricultural and Environmental Sciences.)

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