Tonka Bean Plant Care

Tonka Bean (Coumarouna tetraphylla) belongs to the Fabaceae family within the Coumarouna genus. Tonka Bean is native to Northern South America. Tonka Bean is also known as Tonquin Bean, Cumaru.

Tonka Bean displays a tall, spreading tree growth habit, reaching up to 30 ft tall with a spread of approximately 20 ft. Tonka Bean produces fragrant clusters of small white flowers.

Leaf size: approximately 6 inches.

Water a young or newly planted Tonka Bean every 7–14 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established trees mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Tonka Bean thrives in full sun to partial shade.

Coumarouna tetraphylla tolerates temperatures of 60–85°F. Tonka Bean prefers humidity levels of 40–70%.

Well-draining loamy soil with added organic matter for nutrients. Good drainage is essential for Tonka Bean to prevent waterlogging, which leads to root rot and fungal issues.

Feed Tonka Bean every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established trees 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 loamy soil with added organic matter for nutrients. Avoid low spots where water collects after rain.

Tonka Bean is suited to USDA Zone 11a – 12b.

Plant container-grown or balled-and-burlapped trees in spring or early autumn, setting the root flare at soil level, and water well after planting.

Tonka Bean can spread to about 20 ft (6.1 m) and reach about 30 ft (9 m) tall. Space plants about 20 ft (6.1 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 tree spacing calculator.

Prune Tonka Bean 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 tree in one year.

Tonka Bean is frost-tender (hardy to USDA zone 11). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Tonka Bean can be propagated through seeds, softwood cuttings.

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

Tonka Bean is susceptible to aphids, leafhoppers, 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.

Tonka Bean grows outdoors in USDA Zone 11a – 12b. It survives winters down to planting zone 11a. Tonka Bean is native to Northern South America. In cooler regions, grow Tonka Bean as a houseplant or bring it indoors before the first frost.