Plant Profile: Coral Bean

By Jan Allyn

Reprinted from The Understory Aug.-Sep. 2006
Illustration by Cathy Vogelsong

Illustration © Cathy Vogelsong

Coral bean, Erythrina herbacea, is also known as cherokee bean or cardinal spear. It is a spiny shrub with an open, upright habit that grows to 20 feet in height in frost-free south Florida but elsewhere is much smaller. Its bright green leaves have three lobes, and its branches are armed with sharp, spiny prickles. In spring it produces two-foot long racemes of scarlet, tubular flowers that attract hummingbirds and are pollinated by insects. The flowers appear before the plant has completely leafed out and are held above the sparse foliage. They are followed by bean pods that hold from 2 to 8 bright red beans about 3/8" in length. These seeds may be beautiful but they are also extremely toxic; reportedly their derivatives have been used to make rat poison and to paralyze fish.

Coral bean is found throughout Florida and is recommended for USDA zones 8-11. It is extremely drought tolerant and fairly frost-resistant. Coral bean has a very large, woody root structure which allows it to survive even our coldest winters. Like many other members of the bean family, it can fix nitrogen into the soil. Though it is sometimes called cardinal spear, don't confuse it with cardinal flower, which is a wetland plant! Coral bean prefers well-drained, sandy or loamy soil in full to partial sun and is moderately salt tolerant, making it useful for coastal landscapes. Coral bean is an interesting plant for the landscape, best used as a barrier shrub or as an accent planting. While its spectacular scarlet flowers are a show-stopper, its thorny nature makes it undesirable for high-traffic areas.

Coral bean can be propagated by cuttings, but the seeds are very easy to start. Use an emery board to sand away a spot on the outer seed covering until a small hole develops. Then soak the seeds in water overnight and plant them in pots. I have found that they usually sprout within a week or two.

Published on  06.01.2013