Petrocosmea kerrii Plant Care

Petrocosmea kerrii (Petrocosmea kerrii) belongs to the Gesneriaceae family within the Petrocosmea genus.

Petrocosmea kerrii displays a low rosette, clumping habit growth habit, reaching up to 0.5 ft tall with a spread of approximately 0.5 ft. Petrocosmea kerrii produces tubular flowers in shades of purple, pink, or white.

Leaf size: approximately 2 inches.

Water a young or newly planted Petrocosmea kerrii 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.

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

Petrocosmea kerrii tolerates temperatures of 60–75°F. Petrocosmea kerrii prefers humidity levels of 50–70%. A pebble tray or humidifier helps maintain adequate moisture around the plant.

Well-draining, humus-rich soil with added perlite for extra drainage. Good drainage is essential for Petrocosmea kerrii to prevent waterlogging, which leads to root rot and fungal issues.

Feed Petrocosmea kerrii 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, humus-rich soil with added perlite for extra drainage. Avoid low spots where water collects after rain.

Petrocosmea kerrii is suited to USDA Zone 13a.

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.

Petrocosmea kerrii can spread to about 1 ft (0.2 m) and reach about 1 ft (0 m) tall. Space plants about 1 ft (0.2 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 plant spacing calculator.

Prune Petrocosmea kerrii 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.

Petrocosmea kerrii 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.

Petrocosmea kerrii can be propagated through leaf cuttings, division, seeds. Similar propagation techniques also apply to forrest's petrocosmea plant care, which shares the same genus.

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

Petrocosmea kerrii is susceptible to aphids, spider mites, mealybugs. 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.

Petrocosmea kerrii grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. In cooler regions, grow Petrocosmea kerrii as a houseplant or bring it indoors before the first frost.