Ammannia coccinea Plant Care

Ammannia coccinea (Ammannia arnhemica) belongs to the Lythraceae family within the Ammannia genus. Ammannia coccinea is native to northern Australia.

Ammannia coccinea displays an upright, spreading shrub growth habit, reaching up to 2 ft tall with a spread of approximately 3 ft. Ammannia coccinea produces small, colorful clusters of blooms.

Leaf size: approximately 4 inches.

Water a young or newly planted Ammannia coccinea every 4–7 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.

Ammannia coccinea thrives in full sun to partial shade.

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

Rich, loamy soil with good drainage. Good drainage is essential for Ammannia coccinea to prevent waterlogging, which leads to root rot and fungal issues.

Feed Ammannia coccinea 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 rich, loamy soil with good drainage. Avoid low spots where water collects after rain.

Ammannia coccinea 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.

Ammannia coccinea can spread to about 3 ft (0.9 m) and reach about 2 ft (1 m) tall. Space plants about 3 ft (0.9 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 Ammannia coccinea 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.

Ammannia coccinea 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.

Ammannia coccinea can be propagated through seeds, stem cuttings. Similar propagation techniques also apply to whorled ammannia plant care, which shares the same genus.

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

Ammannia coccinea 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.

Ammannia coccinea grows outdoors in USDA Zone 13b. It survives winters down to planting zone 13b. Ammannia coccinea is native to northern Australia. In cooler regions, grow Ammannia coccinea as a houseplant or bring it indoors before the first frost.