Sydney Red Gum Plant Care

Sydney Red Gum (Angophora costata) belongs to the Myrtaceae family within the Angophora genus. Sydney Red Gum is native to eastern Australia. Sydney Red Gum is also known as Smooth-barked Apple, Rusty Gum, Brushwood.

Sydney Red Gum displays a tall, spreading tree growth habit, reaching up to 50 ft tall with a spread of approximately 30 ft. Sydney Red Gum produces white or cream-colored clusters of small flowers.

Leaf size: approximately 6 inches.

Water a young or newly planted Sydney Red Gum 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.

Sydney Red Gum thrives in full sun.

Angophora costata tolerates temperatures of 50–90°F. Sydney Red Gum prefers humidity levels of 40–70%.

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

Feed Sydney Red Gum 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 loam with added organic matter. Avoid low spots where water collects after rain.

Sydney Red Gum is suited to USDA Zone 12a.

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.

Sydney Red Gum can spread to about 30 ft (9.1 m) and reach about 50 ft (15 m) tall. Space plants about 30 ft (9.1 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 Sydney Red Gum 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.

Sydney Red Gum is frost-tender (hardy to USDA zone 12). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Sydney Red Gum can be propagated through seeds, cuttings. Similar propagation techniques also apply to bakers apple plant care, which shares the same genus.

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

Sydney Red Gum is susceptible to borers, scale insects, leaf-eating 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.

Sydney Red Gum grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Sydney Red Gum is native to eastern Australia. In cooler regions, grow Sydney Red Gum as a houseplant or bring it indoors before the first frost.