Clammy Hedge Hyssop Plant Care

Clammy Hedge Hyssop (Gratiola neglecta) belongs to the Plantaginaceae family within the Gratiola genus. Clammy Hedge Hyssop is native to much of North America, including most all of the United States and the southern half of Canada. Clammy Hedge Hyssop is also known as Rough Hedge Hyssop.

Clammy Hedge Hyssop displays a low rosette, spreading groundcover growth habit, reaching up to 0.5 ft tall with a spread of approximately 1 ft. Clammy Hedge Hyssop produces small tubular flowers in shades of white, pink, or purple.

Leaf size: approximately 2 inches.

Water a young or newly planted Clammy Hedge 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.

Clammy Hedge Hyssop thrives in partial to full sun.

Gratiola neglecta tolerates temperatures of 60–80°F. Clammy Hedge Hyssop prefers humidity levels of 40–60%.

Moist, well-draining soil with high organic content. Good drainage is essential for Clammy Hedge Hyssop to prevent waterlogging, which leads to root rot and fungal issues.

Feed Clammy Hedge 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 sun and moist, well-draining soil with high organic content. Avoid low spots where water collects after rain.

Clammy Hedge Hyssop is suited to USDA Zone 13a.

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.

Clammy Hedge 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 Clammy Hedge 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.

Clammy Hedge Hyssop is frost-tender (hardy to USDA zone 13). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Clammy Hedge Hyssop can be propagated through seeds, division of rhizomes.

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

Clammy Hedge Hyssop is susceptible to aphids, spider mites, whiteflies. 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.

Clammy Hedge Hyssop grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. Clammy Hedge Hyssop is native to much of North America, including most all of the United States and the southern half of Canada. In cooler regions, grow Clammy Hedge Hyssop as a houseplant or bring it indoors before the first frost.