Western Australian Swamp Oak Plant Care

Western Australian Swamp Oak (Casuarina obesa) belongs to the Casuarinaceae family within the Casuarina genus. Western Australian Swamp Oak is native to southern continental Australia. Western Australian Swamp Oak is also known as Swamp Oak.

Western Australian Swamp Oak displays a tall, slender tree growth habit, reaching up to 50 ft tall with a spread of approximately 20 ft. Western Australian Swamp Oak produces small, inconspicuous flowers.

Leaf size: approximately 2 inches.

Water a young or newly planted Western Australian Swamp Oak every 14–21 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.

Western Australian Swamp Oak thrives in full sun.

Casuarina obesa tolerates temperatures of 60–90°F. Western Australian Swamp Oak prefers humidity levels of 40–70%.

Well-draining sandy soil with good aeration. Good drainage is essential for Western Australian Swamp Oak to prevent waterlogging, which leads to root rot and fungal issues.

Feed Western Australian Swamp Oak every 8 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 and well-draining sandy soil with good aeration. Avoid low spots where water collects after rain.

Western Australian Swamp Oak is suited to USDA Zone 13a.

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.

Western Australian Swamp Oak can spread to about 20 ft (6.1 m) and reach about 50 ft (15 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 Western Australian Swamp Oak 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.

Western Australian Swamp Oak 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.

Western Australian Swamp Oak can be propagated through seeds, cuttings. Similar propagation techniques also apply to belah plant care, which shares the same genus.

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

Western Australian Swamp Oak is susceptible to scale insects, borers. 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.

Western Australian Swamp Oak grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. Western Australian Swamp Oak is native to southern continental Australia. In cooler regions, grow Western Australian Swamp Oak as a houseplant or bring it indoors before the first frost.