Gray Horsebrush Plant Care

Gray Horsebrush (Tetradymia canescens) belongs to the Asteraceae family within the Tetradymia genus. Gray Horsebrush is native to western North America. Gray Horsebrush is also known as Spineless Horsebrush, Tetradymia canescens.

Gray Horsebrush displays a low, spreading shrub growth habit, reaching up to 2 ft tall with a spread of approximately 4 ft. Gray Horsebrush produces small yellow flowers in clusters.

Leaf size: approximately 1.5 inches.

Water a young or newly planted Gray Horsebrush every 14–21 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.

Gray Horsebrush thrives in full sun.

Tetradymia canescens tolerates temperatures of 50–85°F. Gray Horsebrush prefers humidity levels of 20–60%.

Well-draining sandy soil with low fertility. Good drainage is essential for Gray Horsebrush to prevent waterlogging, which leads to root rot and fungal issues.

Feed Gray Horsebrush every month 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 full sun and well-draining sandy soil with low fertility. Avoid low spots where water collects after rain.

Gray Horsebrush is suited to USDA Zone 4a – 8b.

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.

Gray Horsebrush can spread to about 4 ft (1.2 m) and reach about 2 ft (1 m) tall. Space plants about 4 ft (1.2 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 Gray Horsebrush 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.

Gray Horsebrush is hardy down to USDA zone 4a, so once established it can stay outdoors through winter in that zone and warmer ones.

Water deeply in late autumn before the ground freezes, and spread a 5–8 cm (2–3 in) layer of mulch over the root zone, keeping it away from the trunk.

Young and container-grown shrubs need extra protection: roots in a pot freeze much more easily than roots in the ground.

Gray Horsebrush can be propagated through seeds. Similar propagation techniques also apply to cottonbush plant care, which shares the same genus.

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

Gray Horsebrush is susceptible to aphids, 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.

Gray Horsebrush grows outdoors in USDA Zone 4a – 8b. It survives winters down to planting zone 4a. Gray Horsebrush is native to western North America.