Cow's Horn Plant Care

Cow's Horn (Euphorbia grandicornis) belongs to the Euphorbiaceae family within the Euphorbia genus. Cow's Horn is native to the KwaZulu-Natal province and the Northern Provinces of South Africa and to Mozambique and Eswatini.

Cow's Horn displays a varies by species, can be upright, sprawling, or clumping growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Cow's Horn produces small, often inconspicuous flowers surrounded by colorful bracts.

Leaf size: approximately 4 inches.

Water a young or newly planted Cow's Horn 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.

Cow's Horn thrives in full sun to partial shade.

Euphorbia grandicornis tolerates temperatures of 60–85°F. Cow's Horn prefers humidity levels of 40–60%.

Well-draining sandy soil mix with perlite and gravel. Good drainage is essential for Cow's Horn to prevent waterlogging, which leads to root rot and fungal issues.

Feed Cow's Horn 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 full sun to partial shade and well-draining sandy soil mix with perlite and gravel. Avoid low spots where water collects after rain.

Cow's Horn 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.

Cow's Horn can spread to about 2 ft (0.6 m) and reach about 3 ft (1 m) tall. Space plants about 2 ft (0.6 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 Cow's Horn 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.

Cow's Horn 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.

Cow's Horn can be propagated through stem cuttings, offsets, seeds. Similar propagation techniques also apply to crown of thorns plant care, which shares the same genus.

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

Cow's Horn is susceptible to mealybugs, spider mites, aphids. 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.

Cow's Horn grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. Cow's Horn is native to the KwaZulu-Natal province and the Northern Provinces of South Africa and to Mozambique and Eswatini. In cooler regions, grow Cow's Horn as a houseplant or bring it indoors before the first frost.