Vitex agnus-castus or chaste tree. This member of the Lamiaceae (mint family) is a shrub or small tree native to the Mediterranean. In a true Mediterranean climate, the chaste tree can grow up to 10 ft. tall with an 8 ft. spread.
In Chicago’s USDA Zone 6a/6b climate, V. agnus-castus will suffer significant above-ground die-back each winter but the root mass will survive to produce new growth each year. Chaste tree is likely not hardy much further north without significant winter protection.
Chaste tree produces showy purple multi-flowered blooms from late summer to the first frost, flowering only on new growth. The flowers attract several species of butterflies and bees. Plants grow best in full-sun and well-drained, slightly sandy soils. The leaves of V. agnus-castus bring a unique texture to the garden; leaves are compound, palmate with a grey-green color.
Lurie Garden has only one of these beautiful shrubs. It can be seen from the boardwalk when looking West into the meadow.
|Botanical Name||Vitex agnus-castus|
|Common Name||chaste tree|
|USDA Zone||6 to 9|
|Light Requirement||Full Sun|
|Season(s) of interest||Summer, Fall|
|Height and Spread||
8-10ft x 5-8ft (2.4-3m x 1.5-2.4m)
|Flower Color||Violet, Blue|
Pollinators, Provides Food for Birds
Native to Asia and the Mediterranean
|Location in Lurie Garden||East Meadow, West Meadow|