Annual Mallow Malva arborea

Tree mallow is an herbaceous perennial, flowering shrub in the Mallow family that can be grown as a biennial or an annual, but will require protection from cold and wind if grown as a perennial. It is typically grown in warmer climates, as it is easily damaged by frost. The attractive pink to lavender flowers are early arrivals in spring, last through the summer, and have dark veins running into a dark center.

Tree mallow grows best with medium moisture in well-drained sandy soil and a salty atmosphere. A site in full sun will maximize flower blossoms, but the plant will tolerate partial shade. It also tolerates drought once established. It excretes excess salt through glands on the leaves, so planting in a coastal location will not be a detriment to the plant.  

Remove spent flower spikes to encourage additional flowering. Tree mallow can freely self-seed in the garden unless spent flowers are promptly deadheaded. Given that this plant is a short lived perennial, some self-seeding may be desirable. Cut back to basal foliage in fall, or earlier if plant appearance declines. Tree mallow tolerates pruning and stems may be cut back in spring if shorter plants are desired.

When grown from seed, the shrub can bloom in its first year.  The seeds remain viable for years.  The spread of this plant along the seashore, due to its salt tolerance and self-seeding, has caused problems for nesting seabirds.

Insects, Diseases and Other Plant Problems: 

The stems crack easily. No serious insect or disease problems. Japanese beetles may feed on the foliage.