Culture
Annual. Grow in average, medium moisture, well-drained soils in full sun. Appreciates some light afternoon shade in hot summer climates such as the St. Louis area. Sow seed directly in the garden in spring two weeks before the last frost date. For earlier bloom, start seed indoors 6-8 weeks before last frost date or purchase plants from local nurseries. Set plants out after last frost date. Taller plants may need staking or support. Deadhead spent flowers to extend bloom period. May self-seed in some areas. This annual can be difficult to grow well in the St. Louis area because it prefers summer climates with cool nights and moderate amounts of rain.
Noteworthy Characteristics
Lavatera trimestris, commonly called tree mallow, is an upright annual that grows in a shrubby form to 2-4’ tall. It is noted for its summer to early fall bloom of saucer-shaped, white to pink flowers (to 2-3” wide) that appear singly in the upper leaf axils. Rounded, medium green leaves (to 3” long) have heart-shaped bases and 3-7 shallow lobes. Good cut flower.
Genus name honors J.R. Lavater, 17th-century Swiss physician and naturalist in Zurich.
Problems
No serious insect or disease problems. Root rot and leaf spots may occur. Japanese beetles may chew on foliage and flowers.
Uses
Annual bedding plant. Containers.