Malvastrum spp.
false mallow
Tropical and subtropical Americas (several species now pantropical)
Overview
Malvastrum spp. is a genus of about 15 herbs and subshrubs in the mallow family, Malvaceae, native mainly to the warmer parts of the Americas, with several species now spread as weeds across the tropics. Known broadly as false mallows, plants grow 12-48 inches (30-120 cm) tall with toothed, often hairy leaves and small, five-petaled mallow flowers in yellow to pale orange. The flowers are about 0.5-1 inch (1.5-2.5 cm) across and open in the leaf axils and at the stem tips, followed by the segmented, button-like fruits typical of the family. M. coromandelianum has spread as a roadside and pasture weed across many tropical countries. Plants are tough and drought tolerant but can be short-lived, and several species self-seed freely into open ground. The genus has been repeatedly redefined, so plants are sometimes listed under related mallow genera.
Native Range
Mainly the tropical and subtropical Americas, from the southern United States through Mexico and Central America to South America. Several species, especially M. coromandelianum, have naturalized widely across the tropics of Africa, Asia, and Australia.Suggested Uses
Malvastrum spp. is grown in informal, dry, and wildlife borders for its long season of small yellow flowers, which draw bees. Tougher species are used to cover poor or disturbed ground. In regions where the genus self-seeds aggressively, it is contained or replaced with less weedy plants.How to Identify
Appearance
Size & Dimensions
Height1' - 4'
Width/Spread1' - 2'6"
Bloom Information
Plants flower over a long warm season, mainly summer and autumn, and nearly year-round in frost-free climates. The small yellow mallow flowers open a few at a time in the leaf axils and are visited by bees. Flowering is followed by the segmented fruits, which scatter seed freely.
Detailed Descriptions
Flower Description
Yellow to pale orangeFoliage Description
GreenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Malvastrum spp. grows in full sun in a wide range of well-drained soils, including poor and disturbed ground, and tolerates heat and drought once established. Plants take occasional water in dry spells but rot in constantly wet soil. Most species are frost tender, perennial only in roughly USDA zones 8 to 11, and behave as annuals where winters are cold. Because several species self-seed heavily and can spread as weeds, spent flowers are removed before seed sets where containment matters. Plants are otherwise low-maintenance with few pest problems.Pruning
Plants are sheared back to remove spent flowers and seed heads, which limits self-seeding and keeps growth compact. Leggy stems can be cut back hard to renew the plant. Frost-killed top growth is cleared in spring where plants are grown as short-lived perennials.Container Growing
✓ Suitable for container growing
Minimum container size: 2 gallons