Malva, also called mallow, is in the same family as hollyhocks and hibiscus. A plant with a bushy habit, malva does well as a border or natural fence. The flowers have a paperlike quality and are extremely long lasting, with the entire bush in bloom all summer. Mallow is the common name for these members of the family Malvaceae.
The mallows are a species of herbaceous perennial that can be biennial in the right climate. The blooms come in ranges of pinks, lavender and even a fairly true blue. The plant needs good drainage and will provide you with flowers all season long. The flowers can be either single or double blooms in white, red, lavender, blue and pinks. Tree mallows can grow to 6 feet high but should be pruned back to desired size after blooms have passed. The foliage can get quite weedy toward the end of the season, so the plant will benefit from a hard cutting when it pushes leaves again in spring.
One of the most common members of the family is malva neglecta or common mallow. It is of spreading habit and one of the weedier looking mallows, with small white flowers. Dwarf mallow is a similar flowering plant. Malva sylvestris is also common and has a pale lavender flower with striping. Malva moravia has a deep purple large bloom. The Tree mallows come in a variety of colors and are tall, upright bushes with large hibiscus-shaped blooms. Little mallow grows as a wild plant in Arizona and is called "cheeseweed" for the shape of its seed pods. There are numerous other cultivars, with most being more common in the United Kingdom.
Malva needs a sunny location; it does best in USDA Plant Hardiness Zones 4 through 8. The planting site needs to be a mix of sand and loam to provide adequate drainage. This plant is a heat lover and is even quite drought tolerant; however, it will do best with moderate moisture. The taller mallows need to be situated in the back of the perennial border or along a fence. The creeping type can get 36 inches high and grow as a low bush, so they should be situated near the front of the border.
Soil Preparation and Planting
Malva likes well-drained soil with plenty of organic matter. A couple of weeks prior to planting it is a good idea to loosen soil to 6 inches and work in compost or manure to improve the soil's content. A pH test may be used to determine if the pH is between 5.5 and 7.5. The plant enjoys a medium level of acidity, so it may be necessary to add fertilizers with "ammonium N" to bring the pH down. The planting hole should be 1 inch larger all around, and well-worked soil should be piled around the roots.
The mallows do not require fertilizer in spring as do most flowering bushes. The application of fertilizer will force the plant to produce more leaves, which will keep the plant from getting adequate air. This can promote fungus and mold growth. Dividing the roots in spring will create another plant. The weedier species benefit from this to start a less woody-looking mallow. Apply adequate water to prevent leaf wilt; this will ensure a good growth and plentiful blooms.