Rough Anthospermum Plant Care

Rough Anthospermum (Anthospermum asperuloides) belongs to the Rubiaceae family within the Anthospermum genus. Rough Anthospermum is native to eastern Cameroon and on the island of Bioko. Rough Anthospermum is also known as Star Anthospermum.

Rough Anthospermum displays a low rosette, clumping growth habit, reaching up to 1.5 ft tall with a spread of approximately 1.5 ft. Rough Anthospermum produces small, white, star-shaped flowers in clusters.

Leaf size: approximately 4 inches.

Water a young or newly planted Rough Anthospermum every 7–10 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.

Rough Anthospermum thrives in bright indirect light. Avoid placing Rough Anthospermum in direct, harsh sunlight for extended periods, as this can scorch the foliage.

Anthospermum asperuloides tolerates temperatures of 65–80°F. Rough Anthospermum prefers humidity levels of 50–70%. A pebble tray or humidifier helps maintain adequate moisture around the plant.

Well-draining, slightly acidic soil with added organic matter like peat moss. Good drainage is essential for Rough Anthospermum to prevent waterlogging, which leads to root rot and fungal issues.

Feed Rough Anthospermum 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 bright indirect light and well-draining, slightly acidic soil with added organic matter like peat moss. Avoid low spots where water collects after rain.

Rough Anthospermum is suited to USDA Zone 13b.

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.

Rough Anthospermum can spread to about 2 ft (0.5 m) and reach about 2 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 Rough Anthospermum 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.

Rough Anthospermum 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.

Rough Anthospermum can be propagated through seeds, division of offsets. Similar propagation techniques also apply to south african broom plant care, which shares the same genus.

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

Rough Anthospermum is susceptible to mealybugs, spider mites, scale insects. 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.

Rough Anthospermum grows outdoors in USDA Zone 13b. It survives winters down to planting zone 13b. Rough Anthospermum is native to eastern Cameroon and on the island of Bioko. In cooler regions, grow Rough Anthospermum as a houseplant or bring it indoors before the first frost.