Chaste Tree (Vitex agnus-castus) - A plant profile

Vitex agnus-castus, commonly called Chaste Tree, is often recommended as an alternative to Crape Myrtle (Lagerstroemia) in the South since the latter is so overused. However, in all honesty, the crape myrtle is so lovely, who would tire of it?   

The chaste tree may not be as dramatic as the crape myrtle but it does offer a delicate charm and is a worthy addition to the late summer garden.

The chaste tree gets its name from the mythic legends of its anaphrodisiac properties. Athenian women used the leaves in their beds to keep themselves chaste during the feasts of Ceres. In Rome, virgins carried twigs as a sign of chastity. The tree was sacred to Hestia, the virginal Greek goddess of hearth.

The spicy fruit and seeds of the tree has been used extensively in herbal medicine to aide the symptoms of female hormonal imbalances as well as other ailments ranging from migraines to premenstrual syndrome.

This Mediterranean plant (a native of southern Europe and western Asia) thrives on heat and rapidly becomes a 20 ft. tree or shrub (with a broad spread) in southern climates. In cooler regions, an 8-10 ft. size is more common. It is cold hardy to zone 7 and may completely die back in winter. Growth will quickly recover the following year. If die-back is minimal, gardeners often cut the plant back to within 1-2 feet in early spring. The plant can be grown as a small tree by pruning the plant to 1-3 main branches and selectively removing side branches.

The leaves are dense and gray-green in color. They are aromatic and divided into 5-7 narrow leaflets measuring 2-6 inches in length. There is no fall color. 

 

 

The showy flower clusters begin to appear in late summer (August here in Vancouver, Washington). Visitors to the garden often think it is a buddleia. Several cultivars are available in blue, pink or white. My favorite are the blue-colored blooms which seem to glow from a distance. The branched panicle-type blooms are upright and measure about 12-18 inches long. Bumblebees absolutely love the blooms and swarm the plants when it is in bloom.

Chaste Tree thrives in full sun and moist, well-drained soil. It can tolerant drought. For best results, however, provide regular watering and at least one fertilizing early in the season to ensure a good show of blooms. Deadheading the spent blooms will encourage more blooms although it can be a tedious task due to the sheer number of blooms. 

This is a good plant for a shrub border or used as a specimen. It would make an attractive patio tree.

Key Characteristics

Botanical Name - Vitex agnus-castus

Common Name - Chaste Tree, Monks' Pepper, Hemp Tree, Chasteberry

Type: Large shrub / small tree

Foliage Type: Deciduous

Size - 8-10' tall and wide, larger in warmer climates

Bloom Time - August - September (Pacific Northwest)

Flower color - Blue, pink, white

Leaf color - Gray/Green

Exposure - Full sun

Soil Needs - Average, moist soil

Growth Rate - Fast

Disease Resistance - Excellent

Pruning - Cut back early in season before new growth begins

Hardiness - Zones 7

Pollinator Friendly: Yes

Deer Resistant - Yes

 

Text and photos by Phillip Oliver, Dirt Therapy