Introduction

Chastetree can be grown as a large, deciduous, multistemmed shrub or small, 10 to 15 feet tall tree, and is noteworthy for its showy, summer display (late springtime in the deep South) of fragrant, upwardly-pointing, terminal panicles of white blooms which are quite attractive to butterflies and bees. The tree is often planted where honey is marketed to promote excellent honey production. The trunk is gray and blocky and somewhat ornamental. The sage-scented leaves of the chastetree are shaped liked a hand, or palmate, and were once believed to have sedative effects. Vitex has the common name "chastetree" since Athenian women used the leaves in their beds to keep themselves chaste during the feasts of Ceres. Vitex seeds itself into landscaped beds and can become somewhat weedy.

General Information

Scientific name: Vitex agnus-castus

Pronunciation: VYE-tecks AG-nus-KASE-tus

Common name(s): 'Silver Spire' chastetree, `Silver Spire' vitex

Family: Verbenaceae

USDA hardiness zones: 6B through 11 (Figure 2)

Origin: not native to North America

Invasive potential: not considered a problem species at this time, may be recommended (North, Central, South)

Uses: specimen; container or planter; trained as a standard; deck or patio; highway median

Description

Height: 10 to 15 feet

Spread: 15 to 20 feet

Crown uniformity: irregular

Crown shape: vase, round

Crown density: moderate

Growth rate: fast

Texture: fine

Foliage

Leaf arrangement: opposite/subopposite (Figure 3)

Leaf type: palmately compound

Leaf margin: entire

Leaf shape: lanceolate

Leaf venation: pinnate

Leaf type and persistence: deciduous, fragrant

Leaf blade length: 2 to 4 inches, 4 to 8 inches

Leaf color: green, blue or blue-green

Fall color: no color change

Fall characteristic: not showy

Flower

Flower color: white/cream/gray

Flower characteristics: showy

Fruit

Fruit shape: unknown

Fruit length: unknown

Fruit covering: fleshy

Fruit color: black

Fruit characteristics: does not attract wildlife; not showy; fruit/leaves not a litter problem

Trunk and Branches

Trunk/bark/branches: branches droop; showy; typically multi-trunked; thorns

Pruning requirement: needed for strong structure

Breakage: resistant

Current year twig color: green

Current year twig thickness: thin, medium

Wood specific gravity: unknown

Culture

Light requirement: full sun, partial sun or partial shade

Soil tolerances: clay; sand; loam; acidic; alkaline; well-drained

Drought tolerance: high

Aerosol salt tolerance: moderate

Other

Roots: not a problem

Winter interest: no

Outstanding tree: yes

Ozone sensitivity: unknown

Verticillium wilt susceptibility: unknown

Pest resistance: resistant to pests/diseases

Use and Management

Chastetree is used effectively in the mixed shrubbery border or as a specimen. It is usually seen as a shrub with a multiple trunk but can be trained in the nursery into a tree with one or several trunks if so desired. Occasionally used as a street or median tree since it will not grow up and into powerlines, but branches tend to droop toward the ground and would hinder traffic visibility if planted too close to the street. Median planting would be fine if there is adequate horizontal space for the crown to develop and spread. Since the flowers attract bees, locate it accordingly.

Chastetree prefers a loose, well-drained soil that is moist or on the dry side, not wet, but will tolerate drained clay or sandy soils. The tree often suffers from dieback in organic, mucky, or other soil which is kept too moist, such as in the New Orleans or Dallas areas. Chastetree should be planted in full sun or light shade, and will tolerate hot weather extremely well, moderate salt air exposure and alkaline soil.

In the colder regions (USDA hardiness zones 6b and 7), chastetree can be killed to the ground by severe winters and is more often seen as a multistemmed shrub. Chastetree is a fast-grower and can easily recover its size when cold weather prunes it. Very similar to Vitex negundo, which also is called chastetree, Vitex agnus-castus is not as cold hardy as Vitex negundo (grows in USDA hardiness zone 6a). Vitex agnus-castus may survive in USDA hardiness zone 6a if protected from winter winds.

Several other cultivars are available which offer flower color variety. 'Alba' has white flowers, and 'Rosea' has pink flowers.

Propagate by softwood cuttings in early summer or by seeds.

Pests

No pests are of major concern.

Diseases

Leaf spot can almost defoliate the tree. Root rot can cause decline in soils which are kept too moist.