Wild Hyssop Plant Care

Wild Hyssop (Knowltonia vesicatoria) belongs to the Ranunculaceae family within the Knowltonia genus. Wild Hyssop is native to the southern parts of South Africa. Wild Hyssop is also known as Cape Hyssop.

Wild Hyssop displays a low rosette, spreading ground cover growth habit, reaching up to 0.5 ft tall with a spread of approximately 1 ft. Wild Hyssop produces small, delicate white flowers in clusters.

Leaf size: approximately 2 inches.

Water a young or newly planted Wild Hyssop every 3–5 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.

Wild Hyssop thrives in partial to full shade. The optimal light range is 100–500 lux. Avoid placing Wild Hyssop in direct, harsh sunlight for extended periods, as this can scorch the foliage.

Knowltonia vesicatoria tolerates temperatures of 50–75°F. Wild Hyssop prefers humidity levels of 40–70%.

Moist, well-draining soil rich in organic matter. Good drainage is essential for Wild Hyssop to prevent waterlogging, which leads to root rot and fungal issues.

Feed Wild Hyssop 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 to full shade and moist, well-draining soil rich in organic matter. Avoid low spots where water collects after rain.

Wild Hyssop 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.

Wild Hyssop can spread to about 1 ft (0.3 m) and reach about 1 ft (0 m) tall. Space plants about 1 ft (0.3 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 Wild Hyssop 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.

Wild Hyssop 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.

Wild Hyssop can be propagated through division, seeds. Similar propagation techniques also apply to cape anemone plant care, which shares the same genus.

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

Wild Hyssop is susceptible to aphids, slugs, snails. 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.

Wild Hyssop grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Wild Hyssop is native to the southern parts of South Africa. In cooler regions, grow Wild Hyssop as a houseplant or bring it indoors before the first frost.