Barrel cactus Plant Care

Barrel cactus (Malleostemon tuberculatus) belongs to the Myrtaceae family within the Malleostemon genus. Barrel cactus is native to Western Australia. Barrel cactus is also known as Golden barrel cactus.

Barrel cactus displays a tall, columnar tree growth habit, reaching up to 15 ft tall with a spread of approximately 5 ft. Barrel cactus produces small white flowers in clusters.

Leaf size: approximately 4 inches.

Water a young or newly planted Barrel cactus 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.

Barrel cactus thrives in full sun to partial shade.

Malleostemon tuberculatus tolerates temperatures of 60–85°F. Barrel cactus prefers humidity levels of 40–70%.

Well-draining loamy soil with added organic matter for moisture retention. Good drainage is essential for Barrel cactus to prevent waterlogging, which leads to root rot and fungal issues.

Feed Barrel cactus 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 moisture retention. Avoid low spots where water collects after rain.

Barrel cactus is suited to USDA Zone 9b – 11a.

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.

Barrel cactus can spread to about 5 ft (1.5 m) and reach about 15 ft (5 m) tall. Space plants about 5 ft (1.5 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 tree spacing calculator.

Prune Barrel cactus 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.

Barrel cactus is frost-tender (hardy to USDA zone 9). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Barrel cactus can be propagated through softwood cuttings, air layering. Similar propagation techniques also apply to costate malleostemon plant care, which shares the same genus.

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

Barrel cactus is susceptible to aphids, scale insects, caterpillars. 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.

Barrel cactus grows outdoors in USDA Zone 9b – 11a. It survives winters down to planting zone 9b. Barrel cactus is native to Western Australia. In cooler regions, grow Barrel cactus as a houseplant or bring it indoors before the first frost.