Virginia Marsh St. John's Wort Plant Care

Virginia Marsh St. John's Wort (Triadenum virginicum) belongs to the Hypericaceae family within the Triadenum genus. Virginia Marsh St. John's Wort is native to the central and eastern United States and eastern Canada. Virginia Marsh St. John's Wort is also known as Virginia Marshweed, Swamp St. John's Wort, Marsh St. John's Wort.

Virginia Marsh St. John's Wort displays a low spreading ground cover growth habit, reaching up to 0.5 ft tall with a spread of approximately 1.5 ft. Virginia Marsh St. John's Wort produces small, star-shaped pink or white flowers.

Leaf size: approximately 2 inches.

Water a young or newly planted Virginia Marsh St. John's Wort every 4–7 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established shrubs mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Virginia Marsh St. John's Wort thrives in partial shade to full shade. The optimal light range is 100–500 lux. Avoid placing Virginia Marsh St. John's Wort in direct, harsh sunlight for extended periods, as this can scorch the foliage.

Triadenum virginicum tolerates temperatures of 50–75°F. Virginia Marsh St. John's Wort prefers humidity levels of 40–70%.

Moist, acidic soil with good drainage. Good drainage is essential for Virginia Marsh St. John's Wort to prevent waterlogging, which leads to root rot and fungal issues.

Feed Virginia Marsh St. John's Wort every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established shrubs in good soil often need little extra feeding, so let weak growth or pale foliage guide you.

Stop feeding by late summer so new growth can harden before winter.

The PlantoScan app can remind you when to water and when to fertilize each plant.

Choose a spot with partial shade to full shade and moist, acidic soil with good drainage. Avoid low spots where water collects after rain.

Virginia Marsh St. John's Wort is suited to USDA Zone 12a.

Plant container-grown or balled-and-burlapped shrubs in spring or early autumn, setting the root flare at soil level, and water well after planting.

Virginia Marsh St. John's Wort can spread to about 2 ft (0.5 m) and reach about 1 ft (0 m) tall. Space plants about 2 ft (0.5 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.

Planning a row or hedge? Try the plant spacing calculator.

Prune Virginia Marsh St. John's Wort while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.

If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the shrub in one year.

Virginia Marsh St. John's Wort is frost-tender (hardy to USDA zone 12). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Virginia Marsh St. John's Wort can be propagated through seeds, division.

See all plants toxic to cats and plants toxic to dogs.

Virginia Marsh St. John's Wort is susceptible to aphids, scale insects, spider mites. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.

Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.

Virginia Marsh St. John's Wort grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Virginia Marsh St. John's Wort is native to the central and eastern United States and eastern Canada. In cooler regions, grow Virginia Marsh St. John's Wort as a houseplant or bring it indoors before the first frost.