The Morton Arboretum logo

TREES & plants

Chaste tree

Lavender-blue flower spikes of chastetree

The chaste tree, which is really a shrub, is a good choice for the shrub border or as a specimen. The upright clusters of lavender-blue, summer-blooming flowers and aromatic gray-green leaves attract butterflies.  In northern region, chaste tree should be cut to ground in early spring.

This plant has some cultivated varieties. Go to list of cultivars.

 

Botanical name: 
Vitex agnus-castus
All Common Names: 
Chaste tree
Family (English): 
Verbena
Family (Botanic): 
Verbenaceae
Tree or Plant Type: 
  • Shrub
Native Locale: 
  • Non-native
Landscape Uses: 
  • Specimen
  • Massing
  • Mixed border
  • Container
Size Range: 
  • Medium shrub (5-8 feet)
  • Small shrub (3-5 feet)
Light Exposure: 
  • Full sun (6 hrs direct light daily)
Hardiness Zones: 
  • Zone 6
  • Zone 7
  • Zone 8
Soil Preference: 
  • Moist, well-drained soil
Foliage: 
  • Deciduous (seasonally loses leaves)
Season of Interest: 
  • Early summer
  • Mid summer
  • Late summer
  • Early fall
Flower Color & Fragrance: 
  • Fragrant
  • Blue
  • Purple
Shape or Form: 
  • Oval
  • Upright
Growth Rate: 
  • Fast
More Information: 

Size and form

Often considered a sub-shrub in northern climates.
Plants flower on new wood developed the same year.
May reach 8 to 10 feet high and wide.

Tree & Plant Care

Plants require well-drained soil in full sun.
Marginally hardy. Cut plant to the ground in early spring for best flowering.
Salt tolerant.

Disease, pests, and problems

leaf spots and root rots in too wet soils

Native geographic location and habitat

Southern Europe and western Asia

Attracts birds, butterflies, and pollinators

Birds and butterflies are attracted to flowers

Bark color and texture

Twiggy grey stems get woody abd blocky in appearance

Leaf or needle arrangement, size, shape, and texture

Opposite;  2 to 4 inches long, palmately compound leaves with 5 to 9 lealfets radiating from a central stalk; narrow and elliptical; gray-green in color

Flower arrangement, shape, and size

Purple to lavender, 3 to 6 inch long flower spikes at tips of branches

Fruit, cone, nut, and seed descriptions

A small persistent drup; not showy

Cultivars and their differences

Blue Diddley® Chastetree (Vitex agnus-castus 'SMVACCBD'): A dwarf chaste tree reaching 3 to 6 feet high; laveder-blue spikes; good for containers

Blue Puffball™ Chastetree (Vitex agnus-castus 'PIIVAC-II'): A First Editions® dwarf, 3 feet high and wide,  compact shrub with medium green foliage; deep blue fragrant flower spikes.

Delta Blues™ Chastetree (Vitex agnus-castus 'PIIVAC-I'): An 8 to 10 feet high and wide, upright-spreading to rounded habit; dark, purplish-blue flowers and small shiny, reddish fruit.