Smoothbark St. Johnswort is a striking evergreen shrub native to Florida's xeric uplands, where it thrives in the demanding sandy soils around sink hole ponds and lakes. This narrow, upright plant grows 6 to 10 feet tall and 3 to 5 feet wide with a tree-like character and sparse branching that gives it an almost asparagus-like silhouette. Hardy in zones 7 through 9, it produces showy yellow flowers from July through August and handles both drought and standing water with remarkable resilience. Listed as an endangered species in Florida, growing this plant in your garden helps preserve a piece of native American botany.
Partial Sun
Moderate
7-9
120in H x 60in W
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High
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The sparsely branched, columnar form of this shrub creates architectural interest that few other plants in the Hypericum family can match. It tolerates the full spectrum of wet conditions, from temporary flooding to prolonged drought, making it exceptionally adaptable to the unpredictable water patterns of Southeast gardens. The smooth bark that gives this species its common name adds another layer of visual appeal, especially in winter when the evergreen foliage and pale stems catch winter light.
Smoothbark St. Johnswort is grown primarily as an ornamental shrub for its distinctive columnar form and summer flowers. Its narrow, upright habit and tree-like character make it suited to vertical accent planting in gardens where you need strong architectural structure without taking up much horizontal space. The evergreen foliage and showy blooms also provide visual interest across multiple seasons.
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Prune lightly to maintain the naturally narrow, upright form and sparse branching habit that gives this shrub its distinctive character. Remove any crowded growth or crossing branches to preserve the tree-like appearance. Pruning is best done in late winter or early spring before new growth emerges.
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“Smoothbark St. Johnswort is endemic to a small region of the Florida panhandle, confined historically to well-drained sandy soils on the slopes and margins of sink hole ponds and lakes in Bay and Washington Counties. Its narrow geographic range and specialized habitat made it vulnerable to collection pressure and habitat loss, leading to its listing as an endangered species in Florida. Growing this plant serves as both a horticultural achievement and an act of conservation, connecting gardeners to the effort to preserve a genuinely rare native plant.”