Erythrina herbacea is a native shrub or small tree of the southeastern United States and northeastern Mexico, grown for its long scarlet tubular blooms in spring and early summer that reliably attract hummingbirds, followed by showy pods that split open to reveal glossy red seeds. It goes by several regional names including Eastern Coralbean, Cherokee Bean, and Mamou in South Louisiana. The combination of wildlife value and tolerance of hot, dry, sandy sites makes it a standout in native plantings along the Gulf and Atlantic coastal plains.
In zones 7–8 the stems are killed to the ground by frost each winter and the plant regrows vigorously from the root crown, behaving like an herbaceous perennial. In zones 9–11 it builds a woody trunk and can reach 15–20 ft. Stems carry recurved thorns. Heavy mulch over the crown after fall frost protects the root system in the colder end of its range. The plant self-seeds and spreads by root suckers, which can form thicket colonies in warm climates; remove suckers promptly if spread is not wanted.
All parts, particularly the seeds, contain erythrine alkaloids and are toxic to humans and livestock. Indigenous peoples of the Southeast documented ethnobotanical uses of the plant, and the alkaloids have been studied in pharmacological research for sedative and muscle-relaxant properties.
Root rot
Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.
Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.
Fungal leaf spot
Brown or purplish spots on the leaves, often ringed with a yellow halo, that spread and merge in warm, humid, or wet weather; heavily spotted leaves yellow and drop early.
Pick off spotted leaves and clear fallen debris to remove overwintering spores. Improve air circulation by thinning, and water at the base so foliage dries quickly. If it persists, apply a copper- or sulfur-based fungicide at the first sign.