Heat, humidity--and more heat. Gardening in the South can be a challenge because of the area's extreme summer conditions. But there's no reason to despair. There are hundreds of tough plants that will thrive in a Southern garden. Tough plants need little water, grow in ordinary soil and can tolerate the South's mugginess, high temperatures and rainy days.
Mexican sunflower (Tithonia rotundifolia) is a dream annual for Southern gardens. It flowers no-stop all summer, and it does not mind humidity, drought or high heat. Mexican sunflower's fuzzy leaves and stems grow to 6 feet tall, though the Goldfinger cultivar reaches only 3 feet. Loved by hummingbirds and butterflies, its red-orange flowers look like brightly colored daisies. Mexican sunflower prefers full sun but can take partial shade. It needs well-drained soil, but it is drought resistant. Frost will kill this favorite cut flower, but it reseeds easily. It grows in USDA Hardiness Zones 5 to 10.
Yarrow (Achillea millefolium) is an herbaceous perennial with wide, flat clusters of small flowers atop stems with feathery evergreen leaves. Its daisy-like flowers come in yellow, pink, fuchsia, white and red. The gray-green leaves are aromatic and form dense mats, and the plant can reach 3 feet tall. Yarrow prefers poor soil and will not flower well or even thrive if fertilized. It requires full sun and well-drained soil, and it makes an excellent addition to a wildflower garden. Once established, yarrow is resistant to drought. It grows in USDA zones 4 to 8.
Soapwort (Saponaria officinalis), also called bouncing Bet, got its name from its leaves and stems, which will foam when crushed and can be used as soap. Soapwart is a tough perennial ground cover that grows to 2 feet in full sun or part shade and almost any soil. Too rich soil will cause it to flop over. Soapwort has clusters of single or double pink and white flowers. It can tolerate conditions ranging from extreme drought to flooding. Use soapwort in the rock garden, beside a fence or surrounding ornamental grass. It grows in USDA zones 3 to 8.
Beautyberry (Callicarpa americana) is a shrub native to the woodlands of the South. Also called French or Spanish mulberry, it has long, graceful, arching stems loaded with purple berries in clusters at each leaf joint. According to Felder Rushing in his book, "Tough Plants for Southern Gardens," beautyberry needs no attention "even in miserable soil." Butterflies and birds stop at its pink-lilac flowers in late spring, but they are enamored by the berries. Beautyberry grows 6 feet tall and wide, and its toothed leaves fall in late summer. Beautyberry is not particular about its soil--it can be wet or dry, as long as it is well-drained. It prefers dappled shade. Plant in USDA zones 6 to 10.