How to Plant and Grow Mallow

A close relative of hollyhock, mallow is an easy-to-grow, short-lived perennial that is easy to start from seed. Tall stems of small blossoms are held high above softly lobed kidney-shaped foliage that blends in well with larger shrubs and other perennials. Planted once, mallow often reseeds itself for a continuous display of blooms year after year. The flat, buttonlike seed pods resemble tiny wheels of cheese, which inspired mallow's lesser-known name of cheese weed.

Mallow's flowers come in shades of pink, white, purple, red, yellow, or orange, which look stunning when planted in large groups in cottage gardens or borders. Individual flowers comprise five heart-shaped petals, many of which will feature darker veins. The flowers appear from early summer until fall, as long as deadheading takes place to encourage continued blooming. Mallow's large medium-green leaves make a coarsely textured background for its flowers and other nearby plants. Some species are grown specifically for their flowers. Other species are prized for their leaves.

Where to Plant Mallow

Mallow plants are attractive additions to beds, borders, and cottage gardens. Planting mallow in full sun eliminates the need to stake the tall varieties. It grows best in moist, well-drained soil conditions.

How and When to Plant Mallow

After the danger of frost has passed in spring, sow mallow seeds directly in the garden in an area that receives full sun and has some protection from the wind. Sow the seeds 1/8 inch deep and thin the emerging seedlings to 3 feet apart. Mallow plants grow well in ordinary soil as long as it is well-draining. In areas with mild winters, mallow seeds can also be sown in the fall.

Seed-starting indoors is not recommended because mallow doesn't transplant well. Gardeners who want to try should sow seeds in peat pots and disturb the seedlings as little as possible when transplanting them. However, the results may be disappointing.

Mallow Care Tips

Light

Mallow requires full sun to be at its best. It can tolerate a small amount of shade, but the bloom color may be subdued.

Soil and Water

Moist, well-drained soil that is organically enriched is ideal, although ordinary soil is sufficient. Some mallow plants can adjust to dry conditions, but most prefer a moist environment. At first, they benefit from weekly watering, but water them deeply once every 10 to 14 days after they settle in.

Fertilizer

Fertilize mallow plants once a year in late fall or early spring with a slow-release balanced fertilizer with a 10-10-10 NPK ratio. For the amount to use, follow product package instructions.

Pruning

Pruning mallow is unnecessary, but the plant can be trimmed to control its size and increase its vitality. Prune it back short in early spring.

Pests and Problems

Japanese beetles consider the foliage and flowers of this plant to be tasty treats. Mallow is prone to rust (small orange-to-brown blisters on the undersides of leaves), especially during the heat of summer. Although not harmful to the plant, rust can make the plant look ugly. Control rust by removing affected leaves early on and keeping foliage dry.

How to Propagate Mallow

Mallow is easy to grow and start from seed if you choose a location that provides moist, well-drained, organically rich soil and full sun. The latter promotes vigorous growth and reduces the need for staking. Plant the seeds directly in the garden and keep the area moist until plants emerge. Most species of this plant are short-lived perennials; others are annuals or biennials, the latter of which will not bloom during the first season after planting. Stay alert, though, because mallow's enthusiasm for self-sowing can cause it to invade lawns, fields, and roadways.

Types of Mallow

Malva moschata

Small musk-scented rose-pink flowers bloom profusely from early summer to early fall. The leaves also release a musky scent, especially when crushed. Zones 3-8.

Malva sylvestris

Malva sylvestris is the most commonly found mallow. These come in shades of pink and purple, often with darker veining of the blooms. Zones 4-8.

'Zebrina' Tree Mallow

Malva sylvestris 'Zebrina' has 2-inch pinkish flowers brilliantly centered and veined with strong purple. These cluster in the axils of dark green, lobed leaves on shrubby 3-foot stems. Zones 4-8.

Mallow Companion Plants

Obedient Plant

Obedient plant is named for the way flowers that are moved to a new position on the stem stay in place, much to the delight of children. It produces showy, unusual flower spikes with little tubular white, pink, or purple flowers. They're excellent as cut flowers. Square stems carry pairs of mid-green (sometimes variegated), lance-shaped foliage that is toothed along the edges. Obedient plant tolerates most soils but tends to become aggressive when given ample water and full sun.

Balloon Flower

The inflated buds of balloon flowers are fun to pop, and they make great cut flowers. Cut them in the bud stage, and sear the base of the stems to prevent the milky sap from seeping out and fouling the water. Most commonly available in blue-violet, balloon flowers also come in pink and white, as well as shorter forms that are better suited for rock gardens and containers. In fall, the foliage of balloon flowers turns clear gold, so don't cut the plant down too early—enjoy the show! They tolerate light shade but not wet feet or drought.

Globe Thistle

Globe thistle is one of the most elegantly colored plants around. It has fantastical large blue balls of steel blue flowers in midsummer, which would be enough. But making it even more lovely are its large coarse, grayish-green leaves, which set off the flower beautifully. If you can bear to separate them from the foliage, globe thistle makes a great cut flower, lasting for weeks in the vase. It also dries well. It's bothered by few pests or diseases. If it likes its conditions, it will reseed fairly readily. If you want to prevent this, deadhead flowers shortly after they fade.