Culture
Best grown in loose, medium moisture, well-drained soils in full sun. Plant in a sheltered location in USDA Zones 5-6 wherein this shrub is not reliably winter hardy and often suffers winter die back or dies to the ground in severe winters. May be regularly pruned to the ground in early spring and grown in the manner of an herbaceous perennial.
Noteworthy Characteristics
Vitex negundo, commonly called chaste tree, is a deciduous shrub or small, multi-trunked tree which typically grows to 10-15' tall (occasionally larger) in warm winter climates. In cold winter areas (especially USDA Zones 5-6), it is more often grown as a 3-5' tall woody perennial. Features compound palmate, grayish-green leaves with 3-5 lance-shaped leaflets (each leaflet to 4" long) and tiny, fragrant, bluish-lavender lowers appearing in loose, 5-8" long panicles in mid to late summer. This species is generally less ornamental than Vitex agnus-castus but may be slightly hardier.
Genus name comes from the Latin name for V. agnus-castus or chaste tree.
Specific epithet refers to the plant's leaves which resemble those of Acer negundo.
Problems
No serious insect or disease problems. Leaf spot and root rot are occasional problems. Winter hardiness in St. Louis is a problem.
Uses
Interesting foliage and late summer flowers are attractive in shrub borders.