Pumice stoneherb Plant Care

Pumice stoneherb (Petradoria pumila) belongs to the Asteraceae family within the Petradoria genus. Pumice stoneherb is also known as Pumice stone, Aster pumilus, Chrysoma pumila.

Pumice stoneherb displays a low rosette, spreading growth habit, reaching up to 0.5 ft tall with a spread of approximately 1 ft. Pumice stoneherb produces small yellow daisy-like flowers in clusters.

Leaf size: approximately 2 inches.

Water a young or newly planted Pumice stoneherb 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.

Pumice stoneherb thrives in full sun to partial shade.

Petradoria pumila tolerates temperatures of 50–80°F. Pumice stoneherb prefers humidity levels of 40–60%.

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

Feed Pumice stoneherb 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 sandy loam with added organic matter. Avoid low spots where water collects after rain.

Pumice stoneherb is suited to USDA Zone 12a.

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.

Pumice stoneherb can spread to about 1 ft (0.3 m) and reach about 1 ft (0 m) tall. Space plants about 1 ft (0.3 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 Pumice stoneherb 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.

Pumice stoneherb 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.

Pumice stoneherb can be propagated through seeds, division of clumps.

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

Pumice stoneherb is susceptible to aphids, whiteflies, spider mites. 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.

Pumice stoneherb grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. In cooler regions, grow Pumice stoneherb as a houseplant or bring it indoors before the first frost.