Rosette Rockcress Plant Care

Rosette Rockcress (Notothlaspi rosulatum) belongs to the Brassicaceae family within the Notothlaspi genus. Rosette Rockcress is native to New Zealand. Rosette Rockcress is also known as Rosulate Penny Cress.

Rosette Rockcress displays a low rosette, spreading growth habit, reaching up to 0.5 ft tall with a spread of approximately 1 ft. Rosette Rockcress produces small white or purple flowers in clusters.

Leaf size: approximately 2 inches.

Water a young or newly planted Rosette Rockcress 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.

Rosette Rockcress thrives in full sun to partial shade.

Notothlaspi rosulatum tolerates temperatures of 50–75°F. Rosette Rockcress prefers humidity levels of 40–70%.

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

Feed Rosette Rockcress 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.

Rosette Rockcress is suited to USDA Zone 7a – 8b.

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.

Rosette Rockcress 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 Rosette Rockcress 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.

Rosette Rockcress is hardy down to USDA zone 7a, 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.

Rosette Rockcress can be propagated through seeds, division of offsets. Similar propagation techniques also apply to australian notothlaspi plant care, which shares the same genus.

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Rosette Rockcress is susceptible to aphids, cabbage worms, flea beetles. 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.

Rosette Rockcress grows outdoors in USDA Zone 7a – 8b. It survives winters down to planting zone 7a. Rosette Rockcress is native to New Zealand.