Thermal Riceflower Plant Care

Thermal Riceflower (Pimelea prostrata subsp. thermalis) belongs to the Thymelaeaceae family within the Pimelea genus. Thermal Riceflower is native to New Zealand and has small white flowers and blue green leaves.

Thermal Riceflower displays a compact, bushy shrub growth habit, reaching up to 2.5 ft tall with a spread of approximately 3 ft. Thermal Riceflower produces small clusters of pink, white, or yellow flowers.

Leaf size: approximately 2 inches.

Water a young or newly planted Thermal Riceflower every 7–10 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established shrubs mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Thermal Riceflower thrives in full sun to partial shade.

Pimelea prostrata subsp. thermalis tolerates temperatures of 60–75°F. Thermal Riceflower prefers humidity levels of 50–70%. A pebble tray or humidifier helps maintain adequate moisture around the plant.

Well-draining acidic soil mix with added organic matter like peat moss or pine bark. Good drainage is essential for Thermal Riceflower to prevent waterlogging, which leads to root rot and fungal issues.

Feed Thermal Riceflower every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established shrubs 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 organic matter like peat moss or pine bark. Avoid low spots where water collects after rain.

Thermal Riceflower is suited to USDA Zone 8b – 11a.

Plant container-grown or balled-and-burlapped shrubs in spring or early autumn, setting the root flare at soil level, and water well after planting.

Thermal Riceflower can spread to about 3 ft (0.9 m) and reach about 3 ft (1 m) tall. Space plants about 3 ft (0.9 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 plant spacing calculator.

Prune Thermal Riceflower 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 shrub in one year.

Thermal Riceflower is hardy down to USDA zone 8b, so once established it can stay outdoors through winter in that zone and warmer ones.

Water deeply in late autumn before the ground freezes, and spread a 5–8 cm (2–3 in) layer of mulch over the root zone, keeping it away from the trunk.

Young and container-grown shrubs need extra protection: roots in a pot freeze much more easily than roots in the ground.

Thermal Riceflower can be propagated through softwood cuttings, seeds. Similar propagation techniques also apply to coastal rice flower plant care, which shares the same genus.

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

Thermal Riceflower is susceptible to aphids, spider mites, 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.

Thermal Riceflower grows outdoors in USDA Zone 8b – 11a. It survives winters down to planting zone 8b. Thermal Riceflower is native to New Zealand and has small white flowers and blue green leaves.