Bastard Cress Plant Care

Bastard Cress (Calepina irregularis) belongs to the Brassicaceae family within the Calepina genus. Bastard Cress is native to Mediterranean Europe, northwestern Africa, Western Asia to Iran and Turkmenistan, the Caucasus, and southern European Russia. Bastard Cress is also known as Vinegar Weed.

Bastard Cress displays a low rosette, spreading ground cover growth habit, reaching up to 0.5 ft tall with a spread of approximately 1 ft. Bastard Cress produces small clusters of white or purple flowers.

Leaf size: approximately 2 inches.

Water a young or newly planted Bastard Cress 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.

Bastard Cress thrives in full sun to partial shade.

Calepina irregularis tolerates temperatures of 50–75°F. Bastard Cress prefers humidity levels of 40–70%.

Well-draining loamy soil with added compost for nutrients. Good drainage is essential for Bastard Cress to prevent waterlogging, which leads to root rot and fungal issues.

Feed Bastard Cress 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 loamy soil with added compost for nutrients. Avoid low spots where water collects after rain.

Bastard Cress is suited to USDA Zone 6a – 10b.

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.

Bastard Cress 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 Bastard Cress 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.

Bastard Cress is hardy down to USDA zone 6a, 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.

Bastard Cress can be propagated through seeds, division of clumps.

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

Bastard Cress 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.

Bastard Cress grows outdoors in USDA Zone 6a – 10b. It survives winters down to planting zone 6a. Bastard Cress is native to Mediterranean Europe, northwestern Africa, Western Asia to Iran and Turkmenistan, the Caucasus, and southern European Russia.