Best grown in loose, medium moisture, well-drained soils in full sun. Plant in sheltered locations north of USDA Zone 7. In USDA Zones 5 and 6, this shrub often suffers winter die back or dies to the ground in severe winters. It is not considered reliably winter hardy throughout USDA Zone 5. However, even though plants may die to the ground in Zone 5-6 winters, the roots often survive the winter and push up as much as 5' of new growth the following year. Because flowering appears on new growth, this shrub also may be regularly pruned to the ground in early spring and grown in the manner of an herbaceous perennial.
This species of chaste tree is typically grown in warm winter climates as a vase-shaped, deciduous shrub (to 10-15' tall) or trained as a single trunk tree to 20' tall. In cold winter areas in USDA Zones 5-6, it is more often grown as a 3-5' tall herbaceous perennial. Features aromatic, compound, palmate, grayish-green leaves with 5-7 lance-shaped leaflets (each leaflet to 6" long) and tiny, fragrant, lavender to pale violet flowers appearing in loose panicles (to 12" long) in mid to late summer. Flowers are quite attractive to butterflies.
No serious insect or disease problems. Leaf spot and root rot are occasional problems. Winter hardiness in St. Louis is a problem.
Interesting foliage and late summer flowers are attractive in shrub borders.