Introduction
Cut-Leaf 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 lavender 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 highly dissected leaves of Cut-leaf Chastetree are shaped like Cut-leaf Japanese Maple 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 negundo
Pronunciation: VYE-tecks nee-GUHN-doe
Common name(s): Cut-Leaf Chastetree, Cut-Leaf Vitex
Family: Verbenaceae
USDA hardiness zones: 6A through 9B (Fig. 2)
Origin: not native to North America
Invasive potential: invasive non-native
Uses: specimen; highway median
Availability: somewhat available, may have to go out of the region to find the tree
Description
Height: 10 to 18 feet
Spread: 15 to 25 feet
Crown uniformity: irregular
Crown shape: round, spreading
Crown density: open
Growth rate: fast
Texture: fine
Foliage
Leaf arrangement: opposite/subopposite (Fig. 3)
Leaf type: palmately compound
Leaf margin: serrate, incised, parted
Leaf shape: lanceolate
Leaf venation: pinnate
Leaf type and persistence: deciduous, fragrant
Leaf blade length: 2 to 4 inches
Leaf color: green
Fall color: no color change
Fall characteristic: not showy
Flower
Flower color: lavender
Flower characteristics: showy
Fruit
Fruit shape: unknown
Fruit length: unknown
Fruit covering: fleshy
Fruit color: unknown
Fruit characteristics: does not attract wildlife; not showy; fruit/leaves not a litter problem
Trunk and Branches
Trunk/bark/branches: branches droop; not showy; typically multi-trunked; thorns
Pruning requirement: needed for strong structure
Breakage: resistant
Current year twig color: green
Current year twig thickness: thin
Wood specific gravity: unknown
Culture
Light requirement: full sun, partial sun or partial shade
Soil tolerances: clay; sand; loam; slightly alkaline; acidic; well-drained
Drought tolerance: moderate
Aerosol salt tolerance: unknown
Other
Roots: not a problem
Winter interest: no
Outstanding tree: yes
Ozone sensitivity: unknown
Verticillium wilt susceptibility: unknown
Pest resistance: free of serious pests and 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 agnus-castus , which also is called Chastetree, Vitex negundo is more cold hardy (grows in USDA hardiness zone 6a). Vitex agnus-castus may survive in USDA hardiness zone 6a if protected from winter winds.
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.