Marsh Mallow Plant Care

Marsh Mallow (Althaea officinalis) belongs to the Malvaceae family within the Althaea genus. Marsh Mallow is native to Europe, Western Asia and North Africa. Marsh Mallow is also known as Common Marshmallow, White Mallow.

Marsh Mallow displays an upright, bushy shrub growth habit, reaching up to 4 ft tall with a spread of approximately 3 ft. Marsh Mallow produces showy, hollyhock-like flowers in various colors.

Leaf size: approximately 6 inches.

Water a young or newly planted Marsh Mallow 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.

Marsh Mallow thrives in full sun to partial shade.

Althaea officinalis tolerates temperatures of 65–80°F. Marsh Mallow prefers humidity levels of 40–60%.

Rich, well-draining soil with added compost or aged manure. Good drainage is essential for Marsh Mallow to prevent waterlogging, which leads to root rot and fungal issues.

Feed Marsh Mallow 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 rich, well-draining soil with added compost or aged manure. Avoid low spots where water collects after rain.

Marsh Mallow is suited to USDA Zone 3a – 9b.

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.

Marsh Mallow can spread to about 3 ft (0.9 m) and reach about 4 ft (1 m) tall. Space plants about 3 ft (0.9 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 Marsh Mallow 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.

Marsh Mallow is hardy down to USDA zone 3a, 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.

Marsh Mallow can be propagated through seeds, stem cuttings. Similar propagation techniques also apply to armenian hollyhock plant care, which shares the same genus.

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

Marsh Mallow is susceptible to aphids, spider mites, japanese 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.

Marsh Mallow grows outdoors in USDA Zone 3a – 9b. It survives winters down to planting zone 3a. Marsh Mallow is native to Europe, Western Asia and North Africa.