Horticulture: Extension: Gold Medal Plants

2003 Gold Medal Winners

Mexican Zinnia (Zinnia angustifolia 'Star Series')
Summer Annual * Full Sun

Mexican Zinnia Star Gold

Mexican Zinnia Star White

Who wouldn't want an annual flower that thrives with little care; tolerates drought, heat and humidity; and bloom nonstop from spring until fall frost! If that sounds too good to be true, then you need to try the 'Star Series' of Mexican Zinnia, Zinnia angustifolia, and see for yourself how bulletproof this annual really is. 'Star Gold,' 'Star Orange,' 'Star White' and 'Starbright Mixture' make up the Star Series, giving the gardener a choice of planting solid colors or color combinations.

As the name implies, Mexican Zinnia is native to the hot, dry regions of Mexico, where average annual rainfall is less than half that in Georgia. The plant is genetically programmed to withstand summer drought and actually prefers dry soils over moist, soggy conditions. Once established, Mexican Zinnia will provide a fiesta of color in your landscape while requiring little routine maintenance.

Plant Characteristics:

Mexican Zinnias grow more compact and have smaller leaves than other types of zinnias. Leaves are narrow and lance-shaped, ½ to 3 inches long and less than ½ inch wide. Stems have numerous side branches, each terminating in a daisy-like flower 1½ to 2 inches wide with a purplish-orange center. Plants are low-growing and mound-shaped, 12 to 18 inches high and 12 inches wide. Mexican Zinnias are resistant to mildew and bacterial leaf spots that plague other types of zinnias, and insect pests are seldom a problem.

Cultural Requirements:

Mexican Zinnias prefer full sun and well-drained soils. They can be grown from seed and transplanted soon after the last frost. Space plants 12 to 18 inches apart.

Although Mexican zinnias are noted for their toughness, they'll perform better when planted in soils enriched with organic matter. Uniformly incorporating 4 inches of compost or composted animal manure to a 12-inch depth is commonly recommended for summer bedding plants. For season-long feeding, place a tablespoon of a slow-release fertilizer such as Osmocote directly in the planting hole beneath the plant. Look for a slow-release fertilizer with an 8- to 12-month release duration for summer months.

Finish the bed by applying pine straw or pine-bark mini nuggets 3 to 4 inches thick on the surface. Then water thoroughly to settle the soil and to minimize transplant shock.

Once established, Mexican Zinnias are low-maintenance. Unlike other types of zinnias, they don't require dead-heading (removal of old blossoms). The old blossoms simply fade into the background as new onces take their places.

Miss Huff Lantana (Lantana camara 'Miss Huff')
Herbaceous Perennial * Full Sun * Hardiness Zones 7 to 8

Most Georgia gardeners have a fond appreciation for lantanas and their ability to thrive under harsh conditions. New Gold Lantana, a Georgia Gold Medal Winner in 1995, became one of the most widely planted bedding plants in Georgia soon after earning the award. While most lantanas lack winter hardiness and are grown as summer annuals, Miss Huff Lantana, Lantana camara 'Miss Huff,' is a proven perennial as far north as hardiness zone 7.

Miss Huff Lantana was found in a garden in north Georgia and introduced by Goodness Grows Nursery in Lexington, Georgia. Like other lantanas, it's "tough as nails," blooming continuously from spring until fall frost. It attracts butterflies like magnets, while the pungent foliage repels deer, a growing landscape pest in Georgia. Drought tolerance is another outstanding feature that should not be overlooked.

Plant Characteristics:

Miss Huff Lantana has a shrub-like growth habit, reaching 5 to 6 feet tall and 10 feet wide at maturity. Leaves are opposite, 2 to 3 inches wide and 3 to 5 inches long with a hairy upper leaf surface and pronounced veins underneath. The leaves emit a pungent odor when crushed.

Flowers are dense heads, 2 to 3 inches wide, composed of many small florets, each about 1/8 inche across. Florets range in color from pink to orange and yellow, depending on their stage of maturity, giving the flower a multicolored appearance. Flowers are borne continuously throughout the growing season on short stalks arising from the leaf axils along the stems. Flowers are followed by pea-size green fruits that turn black with maturity. The fruits, however, produce no viable seeds, so unwanted seedlings are not a problem.

Like other lantanas, Miss Huff Lantana dies back after the first fall frost. New growth emerges from the crown or base of the plant each spring, provided the winter is not too harsh.

Cultural Requirements:

Miss Huff Lantana is a widely adaptable plant, growing in the beach sands of coastal Georgia and the heavy clays of north Georgia. It thrives in harsh, unirrigated highway islands and sidewalk plantings where other plants struggle. However, growth and performance will be enhanced when the plant is provided moist, fertile soils enriched with organic matter.

Since Miss Huff Lantana gets large, it's best to space plants 6 feet apart. A group of 3 to 5 plants will fill a large space.

A complete, balanced fertilizer such as 10-10-10 or 13-13-13 applied at 1 pound per 100 square feet at planting time and when new shoots emerge in the spring will provide adequate nutrition in most situations.

Although it's tempting to prune back the old foliage soon after fall frost singes the foliage, cold hardiness increases when pruning is delayed until early spring, just as new growth begins.

Crossvine (Bignonia capreolata)
Evergreen Flowering Vine * Full sun to partial shade * Hardiness Zones 6 to 9

Crossvine is a vigorous climber, reaching 30 to 50 feet. Thread-like tendrils along the stem wrap around nearby objects and help the plant climb up a structure. Small, root-like disks along the tendrils help them attach to concrete, brick and other porous structures. Leaves are lustrous, dark green, 2 to 6 inches long and ½ to 2 inches wide, turning reddish-purple in winter.

Flowers are tubular, 1½ to 2 inches long and up to 1½ inches wide, brownish-red with a yellow-orange throat. They are borne in clusters of 2 to 5 flowers on short stalks in April. Flowering continues for three to four weeks with a few additional flowers opening sporadically throughout the season. They have a pleasant, mocha-like fragrance.

Plant Characteristics:

Cultural Requirements:

Crossvine prefers moist, acidic, well-drained soils and full sun to partial shade. Prune as necessary after flowering to control growth.

A complete garden fertilizer such as 16-4-8 applied in late winter or after spring pruning is sufficient for maintaining health and vigor.

Summer cuttings are easy to root.

Henry Anise-tree (Illicium henryi)
Evergreen Shrub * Shade to partial shade * Hardiness Zones 7 to 9

Henry Anise Tree

Henry Anise-tree, Illicium henryi, is not really a tree but a coarse-textured evergreen shrub growing 6 to 8 feet tall and wide. It thrives in dense shade and is an excellent choice for woodland settings. Added benefits are glossy, pest-free foliage and crimson-pink flowers borne in April to May. Deer avoid Henry Anise-tree and its pungent aromatic foliage, which smells like licorice when crushed.

Michael Dirr, professor of horticulture at the University of Georgia, calls Henry Anise-tree a "little-known gem in the American garden." It's a choice companion shrub for rhododendron, camellia, stewartia and other shade-loving plants.

Several species of Anise-trees are on the market today, but Henry Anise-tree is the cream of the crop. While other Anise-trees thin out in dense shade, Henry maintains a dense, pyramidal growth form, mimicking rhododendron but requiring must less fuss.

Plant Characteristics:

Henry Anise-tree is a broadleaf, evergreen shrub reaching 8 feet at maturity. The coarse-textured leaves are 4 to 6 inches long and 1 to 1½ inches wide with a leathery texture and glossy green color.

Single flowers having 10 to 14 petals appear in April to May on stalks emerging from the leaf axils. Flower color ranges from pink to deep crimson and are among the showiest of all the Anise-tree species.

Naturally occurring organic compounds in the leaf have been shown to be toxic to some insects while repelling others.

Cultural Requirements:

Plant Henry Anise-tree in shade or partial shade in moist, well-drained soils. A group of three to five plants planted on diagonal spacing, 6 to 8 feet apart, in the perennial border looks particularly nice.

Occasional irrigation during periods of limited rainfall and mulching to conserve moisture in the soil will keep Henry Anise-tree looking its best. A complete, granular fertilizer such as 16-4-8 or 12-4-8 applied in early spring provides adequate nutrition.

Prune as necessary after bloom to encourage a more uniform shape.

Chinese Fringetree (Chionanthus retusus)
Evergreen Shrub * Shade to partial shade * Hardiness Zones 7 to 9

Chinese Fringetree

It's hard to get tired of dogwoods, but there's hardly a landscape in Georgia without one. So if you dare to be different and want a small flowering tree that is sure to rank among the "Best-in-Show" in your neighborhood, consider planting Chinese Fringetree, Chionanthus retusus.

"Billowing clouds of white" is perhaps the best description of Chinese Fringetree when it is in bloom. Its pure white, strap-like flowers are borne in profusion on new growth, often in such large numbers that they mask the foliage. It also blooms about a month later then dogwood, thus extending the spring floral display.

Another outstanding feature of Chinese Fringetree is its grayish-brown bark that exfoliates into paper-like curls as the plant ages. Pest resistance and drought tolerance are other admirable qualities that helped earn Chinese Fringetree a Gold Medal Award in 2003.

Plant Characteristics:

Chinese Fringetree cn be grown as a large, multistem shrub or small tree, reaching 15 to 25 feet at maturity. Leaves are oval, 3 to 4 inches in diameter, leathery and lustrous dark green. Although the tree is deciduous, the leaves often persist into December. Flowers have long, narrow, snow-white petals and are borne in profusion on new growth in late April to early May. Plants are either male or female, but both produce showy flowers. Female plants produce dark blue, pea-size fruit that ripen in fall. The bark exfoliates as the plant ages.

Cultural Requirements:

Chinese Fringetree adapts to full sun or partially shaded sites. Moist, well-drained soils are preferred, but the tree has a good degree of drought tolerance once established. Prune after flowering, if necessary, to encourage branching and a desired shape. Fertilize in early spring with a complete fertilizer such as 16-4-8 or 12-4-8.1

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