River Anacardium Plant Care

River Anacardium (Semecarpus riparius) belongs to the Anacardiaceae family within the Semecarpus genus. River Anacardium is native to New Caledonia. River Anacardium is also known as River Marking Nut.

River Anacardium displays a medium-sized tree growth habit, reaching up to 30 ft tall with a spread of approximately 20 ft. River Anacardium produces small greenish-yellow flowers in clusters.

Leaf size: approximately 6 inches.

Water a young or newly planted River Anacardium 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.

River Anacardium thrives in full sun to partial shade.

Semecarpus riparius tolerates temperatures of 60–85°F. River Anacardium prefers humidity levels of 40–70%.

Well-draining sandy loam with added organic matter. Good drainage is essential for River Anacardium to prevent waterlogging, which leads to root rot and fungal issues.

Feed River Anacardium 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 sandy loam with added organic matter. Avoid low spots where water collects after rain.

River Anacardium is suited to USDA Zone 10b – 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.

River Anacardium 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 River Anacardium 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.

River Anacardium is frost-tender (hardy to USDA zone 10). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

River Anacardium can be propagated through seeds, stem cuttings. Similar propagation techniques also apply to burmese marking nut plant care, which shares the same genus.

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

River Anacardium is susceptible to aphids, scale insects, 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.

River Anacardium grows outdoors in USDA Zone 10b – 12b. It survives winters down to planting zone 10b. River Anacardium is native to New Caledonia. In cooler regions, grow River Anacardium as a houseplant or bring it indoors before the first frost.