For long lasting plants in South Carolina, look for trees and shrubs that are slow growers and develop a good root system. Perennial flowers last for years, whereas annuals only last for one year and biennials for two. Pick plants that are native to South Carolina; they have become adapted to the climate over generations. No matter how long lasting a plant is naturally, the gardener has to give it the conditions of light and soil that the plant needs or the life span will be shorter than it should be.
Washington hawthorn (Crataegus phaenopyrum) is a member of the rose family. The tree has a slow growth rate, topping out at about 20 feet tall and 20 feet wide. Leaves start out red, turn dark green on top, medium green on the underside and finally burgundy to wine color in the fall. The egg-shaped, lobed leaves measure about 2 inches long. Clusters of white flowers about 2 inches wide cover the tree in early June. The flowers give way to clusters of tiny green fruits that turn orange in October and finally to red-orange in November. The fruit is a favorite snack for both birds and squirrels. Plant Washington hawthorn in full sun or partial shade and a moist, well-drained soil. The tree is hardy in all of South Carolina.
Rosebay rhododendron (Rhododendron maximum) is an evergreen shrub that grows from 8 to 30 feet tall. It has thick, strap-like leaves, dark-green on top and green or rust colored on the underside, that grow from 4 to 8 inches long. Pink or white flowers bloom in June, measure 1 1/2 inches wide and grow in clusters of up to 25 blossoms. Rosebay rhododendron is hardy in all of South Carolina and does best in partial shade and well-drained, organic soil when it is placed where the plant is protected from the wind.
Carolina lupine (Thermopsis villosa) is hardy in all of South Carolina and likes full sun and a soil that is moist to dry and well-drained. The plant can take on the hot, summer sun. Carolina lupine grows from 3 to 5 feet tall with yellow flowers growing in thick clusters at the tips of the stems in early summer. Flowers are followed by seed pods covered in long, shaggy hairs. Gray-green, compound leaves are composed of oval-shaped leaflets up to 3 inches long.
Black cohosh (Actaea racemosa) is hardy in all of South Carolina. The plant grows from 4 to 6 feet tall and 2 to 4 feet wide. Small, cream-white flowers bloom in late summer and early fall, growing in clusters at the tips of the stems. The flowers grow taller than the deep-green leaves. Give black cohosh partial to full shade and moist, organically rich, well-drained soil that is not allowed to completely dry out. Grow in a spot where the plant will be protected from winds.