Hollandaea diabolica Plant Care

Hollandaea diabolica (Hollandaea diabolica) belongs to the Proteaceae family within the Hollandaea genus. Hollandaea diabolica is native to restricted areas of the rainforests of the Wet Tropics region of northeastern Queensland.

Hollandaea diabolica displays a tall, upright shrub growth habit, reaching up to 6 ft tall with a spread of approximately 4 ft. Hollandaea diabolica produces showy clusters of colorful bracts with small flowers.

Leaf size: approximately 8 inches.

Water a young or newly planted Hollandaea diabolica 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.

Hollandaea diabolica thrives in full sun to partial shade.

Hollandaea diabolica tolerates temperatures of 60–80°F. Hollandaea diabolica prefers humidity levels of 40–70%.

Well-draining acidic soil mix with high organic content. Good drainage is essential for Hollandaea diabolica to prevent waterlogging, which leads to root rot and fungal issues.

Feed Hollandaea diabolica 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 acidic soil mix with high organic content. Avoid low spots where water collects after rain.

Hollandaea diabolica 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.

Hollandaea diabolica can spread to about 4 ft (1.2 m) and reach about 6 ft (2 m) tall. Space plants about 4 ft (1.2 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 Hollandaea diabolica 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.

Hollandaea diabolica 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.

Hollandaea diabolica can be propagated through seeds, cuttings. Similar propagation techniques also apply to hollandaea porphyrocarpa plant care, which shares the same genus.

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Hollandaea diabolica is susceptible to spider mites, aphids, scale insects. 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.

Hollandaea diabolica grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. Hollandaea diabolica is native to restricted areas of the rainforests of the Wet Tropics region of northeastern Queensland. In cooler regions, grow Hollandaea diabolica as a houseplant or bring it indoors before the first frost.