Carolina St. John's-wort

Size, growth and what to expect

No source rates its growth, so our growth estimator uses the middle rate, about a foot and a half a year. Most plants grow many stout, bushy stems up to about 15 feet tall and form dense thickets. A slender Florida form stays 1 to 3 feet tall. The needle-like leaves run about half an inch to an inch long.

Clusters of 3 to 15 yellow flowers, each about half an inch across, open at the branch tips from April into July. Each flower has 50 to 80 stamens.

It grows wild on the Coastal Plain from the Florida Panhandle across southern Georgia, with outlying stands in Alabama and in one county each of North and South Carolina. Its home is pond margins, open stream banks, sloughs, ditches, flatwoods and low pinelands.

How to grow Carolina St. John's-wort

Carolina St. John's-wort wants full sun or light shade and a wet soil, such as a pond margin, a stream bank or a low, sandy flat. Set plants 5 feet apart and 5 feet from a wall. At its size it can go within 15 feet of overhead wires.

Saplings ship bare-root or potted. Plant them in a hole wider than the roots and no deeper. Set the crown at the soil line, put the native soil back in, and keep the mulch clear of the stems. Many St. John's-worts need light to sprout, so press the fine seed onto damp, sandy soil in spring without covering it.

Keep the soil wet through the first year. Its stems multiply into a clump over the years, so give it room to spread.

Each flower carries both male and female parts, so there are no male and female plants to pair. Slender capsules about a quarter inch long follow the flowers.