Monk's Pepper Vitex agnus-castus

The chaste tree is a shrub or tree native to Europe and Asia that does best in hot weather. It is a member of the mint family (Lamiaceae). The specific epithet repeats words for "chaste, pure" in two languages, first in Greek and then in Latin.

Chaste tree is hardy in zones 7 to 8. In cooler climates, it can be severely pruned to the ground and will usually regrow.  It can suffer winter dieback or will die to the ground in USDA Zones 5 and 6; however, the roots often survive and push up several feet of new growth the following year.  Pruning can be done in early spring as flowering occurs on new wood. Due to this trait, dieback will not affect flowering.  Prune faded flowers to promote continuous flowering. Flowering will be more spectacular if the plant is heavily pruned after blooming. 

This tree is resistant to damage by deer and is moderately salt tolerant. It has good drought tolerance once established. It freely reseeds and can become weedy. Bees and many other pollinators are attracted to its flowers and foliage.

In warmer climates, it can be trained to grow as a small, single-trunk tree or a large shrub.  Although typically grown as a 10–15-foot shrub, in tree form it can reach heights and widths of up to 20 feet.  This long-lived specimen's rapid growth rate can add up to 24 inches per year in height.

Some smaller cultivars like ‘Blue Diddley' and ‘Blue Puffball’ can be grown as 3-to-6-foot shrubs; other cultivars such as ‘Cooke’s Blue’, ‘Cooke’s Pink’, or ‘Cooke’s Purple’ can grow as tall as 25 to 30 feet with the same spread. There are also many cultivars of various sizes in between.

The Chaste tree is great for the home landscape provided it has plenty of room to grow. The unique foliage and flowers will add interest to the home garden. This plant has the potential to become invasive, especially in southern areas of the country.  Its dry fruit can be a litter issue.

Seasons of Interest:

Bloom: Spring and Summer      Foliage:  Spring and Summer   

Quick ID Hints:

• deciduous tree or shrub with an erect, open, rounded habit
• grayish-green leaves with gray undersides, arranged in leaflets and fragrant when bruised
• fragrant, pink, lavender, or white flowers, arranged in up to 12-inch panicles
• small, purple, globose drupes are present in the fall

Insects, Diseases, and Other Plant Problems: Thrips can cause damage. Root rot can occur in too moist soils.

VIDEO created by Andy Pulte for “Landscape Plant Identification, Taxonomy and Morphology” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.