Plant Profile: Vitex agnus-castus

Chasetree is a non-native shrub or tree that thrives in warm climates. In cooler regions, it can be cut back to the ground and typically will regenerate. In USDA Zones 5 and 6, it may experience winter dieback or die back completely, but its roots often endure, producing several feet of new growth in the following season. Pruning is best done in early spring since the plant flowers on new growth, meaning that dieback does not impact its blooming. To encourage ongoing flowering, remove spent blooms, and a more vibrant display can be achieved by heavily pruning the plant after it has finished blooming.

This tree is resistant to deer damage and has moderate salt tolerance. Once established, it also demonstrates good drought resistance. However, it can reseed prolifically, leading to potential weediness.

In warmer regions, it can be shaped into a small, single-trunk tree or a large shrub. While it is commonly cultivated as a shrub reaching 10 to 15 feet, in tree form, it can grow up to 20 feet tall. This long-lived plant has a rapid growth rate, potentially adding up to 24 inches in height each year.

Certain smaller cultivars, such as ‘Blue Diddley’ and ‘Blue Puffball,’ can be maintained as shrubs between 3 to 6 feet tall, while others like ‘Cooke’s Blue,’ ‘Cooke’s Pink,’ and ‘Cooke’s Purple’ can reach heights of 25 to 30 feet with a similar spread. There are numerous cultivars available in various sizes.

This plant has the potential to become invasive, particularly in southern regions, and its dry fruit can contribute to litter problems.

PESTS AND DISEASES: Thrips may inflict damage on the plant. It serves as the sole known host for Hyalesthus obsoletus and can be strategically planted around vineyards to trap this cicada, acting as a biological control agent. Additionally, root rot may occur in overly moist soils.