Premna thwaitesii Plant Care

Premna thwaitesii (Premna thwaitesii) belongs to the Lamiaceae family within the Premna genus. Premna thwaitesii is native to Sri Lanka.

Premna thwaitesii displays a compact, bushy shrub growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Premna thwaitesii produces small clusters of tiny white or pale pink flowers.

Leaf size: approximately 4 inches.

Water a young or newly planted Premna thwaitesii 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.

Premna thwaitesii thrives in bright indirect light. Avoid placing Premna thwaitesii in direct, harsh sunlight for extended periods, as this can scorch the foliage.

Premna thwaitesii tolerates temperatures of 65–80°F. Premna thwaitesii prefers humidity levels of 50–70%. A pebble tray or humidifier helps maintain adequate moisture around the plant.

Well-draining sandy loam with added organic matter for moisture retention. Good drainage is essential for Premna thwaitesii to prevent waterlogging, which leads to root rot and fungal issues.

Feed Premna thwaitesii 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 bright indirect light and well-draining sandy loam with added organic matter for moisture retention. Avoid low spots where water collects after rain.

Premna thwaitesii is suited to USDA Zone 13b.

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.

Premna thwaitesii can spread to about 2 ft (0.6 m) and reach about 3 ft (1 m) tall. Space plants about 2 ft (0.6 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 Premna thwaitesii 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.

Premna thwaitesii 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.

Premna thwaitesii can be propagated through softwood cuttings, air layering.

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

Premna thwaitesii is susceptible to aphids, spider mites, whiteflies. 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.

Premna thwaitesii grows outdoors in USDA Zone 13b. It survives winters down to planting zone 13b. Premna thwaitesii is native to Sri Lanka. In cooler regions, grow Premna thwaitesii as a houseplant or bring it indoors before the first frost.