Mountain Devil Plant Care

Mountain Devil (Lambertia formosa) belongs to the Proteaceae family within the Lambertia genus. Mountain Devil is native to heathland or open forest, growing in sandstone-based soils. Mountain Devil is also known as Honey Flower.

Mountain Devil displays an upright, bushy shrub growth habit, reaching up to 5 ft tall with a spread of approximately 4 ft. Mountain Devil produces showy clusters of tubular flowers in shades of red, orange, or pink.

Leaf size: approximately 4 inches.

Water a young or newly planted Mountain Devil 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.

Mountain Devil thrives in full sun to partial shade.

Lambertia formosa tolerates temperatures of 50–80°F. Mountain Devil prefers humidity levels of 40–70%.

Well-draining acidic soil mix with added sand and peat moss. Good drainage is essential for Mountain Devil to prevent waterlogging, which leads to root rot and fungal issues.

Feed Mountain Devil 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 added sand and peat moss. Avoid low spots where water collects after rain.

Mountain Devil is suited to USDA Zone 9a – 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.

Mountain Devil can spread to about 4 ft (1.2 m) and reach about 5 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 Mountain Devil 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.

Mountain Devil 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.

Mountain Devil can be propagated through seeds, cuttings. Similar propagation techniques also apply to holly-leaved lambertia plant care, which shares the same genus.

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

Mountain Devil 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.

Mountain Devil grows outdoors in USDA Zone 9a – 11a. It survives winters down to planting zone 9a. Mountain Devil is native to heathland or open forest, growing in sandstone-based soils. In cooler regions, grow Mountain Devil as a houseplant or bring it indoors before the first frost.