Hc

Chapman's St. John's-wort

Hypericum chapmanii

Also called Apalachicola St. John's-wort.

A Florida Panhandle shrub that grows like a small tree, with corky, peeling bark, needle-like leaves and yellow summer flowers.

RareShowy flowersTolerates wet soilBears young

Type: Shrub
Mature height: 7–13 ft
USDA zones: 8–9
Growth rate: Medium
Sun: Full, Part
Soil moisture: Average, Wet
Grows wild in: Swamps and wet flats
Native range: Florida See what is native in your state

Hardiness zones Find your zone by ZIP code

Chapman's St. John's-wort grows wild only in the Florida Panhandle, in flatwoods ponds, dome swamps and the wet edges of pine savannas. It grows like a small tree on a single trunk, with needle-like leaves and a thick, spongy bark that peels in papery sheets. It was first described in 1892 under a name meaning the treelike St. John's-wort, and in 1962 it was renamed for Chapman, who described it. NatureServe ranks it vulnerable. Give it the edge of a pond or a wet, sunny hollow, where it can grow into a little tree with peeling bark.

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. It makes a single-trunked shrub 7 to 13 feet tall, and some stands reach about 16 feet. The trunk can reach 8 inches across at the base, and its fluted, spongy bark peels in thin, papery sheets. The needle-like leaves run a third of an inch to an inch long.

Bright yellow flowers about half an inch across open from June into August, one to three at the branch tips. Each has about 75 stamens. Small capsules a quarter inch long follow, full of tiny seeds.

It grows wild only in the Florida Panhandle, in about ten counties from Santa Rosa east to Franklin. Its home is seasonally flooded flatwoods ponds, dome swamps, small lakes and bogs, often with myrtle dahoon and pond cypress. Pine plantations have taken some of its habitat.

How to grow Chapman's St. John's-wort

Chapman's St. John's-wort wants full sun or light shade and a wet soil that floods for part of the year. In the wild it grows in ponds and hollows that fill and dry with the seasons. Set plants 4 feet apart and 4 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 trunk. In the wild its seed waits in the soil until fire or other disturbance clears the ground, and then many seeds sprout. Press the fine seed onto damp, bare, sandy soil in spring without covering it, since other St. John's-worts need light to sprout.

Keep the soil wet through the first year. Fire kills it, and it comes back only from seed, so keep burns and mowers away from young plants.

Each flower carries both male and female parts, so there are no male and female plants to pair. Seedlings take 3 to 5 years to flower and set seed, and plants live more than 10 years. Birds carry off some of the seed.

Heights and zones are typical ranges for the species in cultivation; local conditions and seed source shift them.

Sources (9)