Acacia longissima Plant Care

Acacia longissima (Acacia longissima) belongs to the Fabaceae family within the Acacia genus. Acacia longissima is native to eastern Australia.

Acacia longissima displays a tall, spreading tree growth habit, reaching up to 30 ft tall with a spread of approximately 20 ft. Acacia longissima produces clusters of small yellow or white flowers.

Leaf size: approximately 4 inches.

Water a young or newly planted Acacia longissima 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.

Acacia longissima thrives in full sun.

Acacia longissima tolerates temperatures of 50–90°F. Acacia longissima prefers humidity levels of 40–70%.

Well-draining sandy soil mix with some organic matter. Good drainage is essential for Acacia longissima to prevent waterlogging, which leads to root rot and fungal issues.

Feed Acacia longissima 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 mix with some organic matter. Avoid low spots where water collects after rain.

Acacia longissima 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.

Acacia longissima 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 Acacia longissima 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.

Acacia longissima 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.

Acacia longissima can be propagated through seeds, cuttings. Similar propagation techniques also apply to gold dust wattle plant care, which shares the same genus.

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Acacia longissima 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.

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