Gardening Tips

Tip 1003


Chaste Tree
(Vitex agnus-castus)


If you like crape myrtle, you'll love Chaste tree, Vitex agnus-castus. It's tough as nails, heat tolerant and cold hardy with good pest resistance and excellent drought tolerance. It flowers consistently throughout summer with a minimum of care.

Chaste tree flowers on new terminal growth. Individual blooms are tiny, about 1/4 inch, but they are borne in masses on large, multi-branched panicles, much like crape myrtle or butterfly bush. Flowers may be are usually blue - lavender, but some cultivars are pink or white.

Like crape myrtle, Chaste tree can be encouraged to repeat bloom in late summer by removing the terminal seed clusters soon after the first bloom finishes. This type of pruning (or deadheading) before mid-July will result in a second floral display in October.

Some desire Chaste tree to be a large shrub. Others a small tree. It can grow 15 to 20 feet tall with an equal spread. Train it as a single-trunk tree or a multi-trunk specimen for use as an accent plant in the landscape.



Plant Characteristics


Plant Type:

Deciduous small tree.

Plant Size:

15 to 20 feet tall with an equal spread.


Blue, lavender, pink or white panicles on terminal growth.


Cultural Requirements



Full sun to partial shade.


Very adaptable - moist to dry.


Granular fertilizer, such as Dr Qs Tree Shrub and Vine food, Liquid such as Gro-Power. In early spring as new growth emerges.


Prune in late winter to shape and to encourage branching. Optional pruning after the first bloom will force new growth and repeat bloom in fall.




Pruning for a Tree

Chaste Tree Before pruning

Chaste Tree After pruning

You can let the Vitex grow naturally into a tree. For more beauty you might want to thin it out a bit each year (as pictured) You should consider removing any suckers (new spouts that grow from the base) periodically in order to maintain the desired tree shape. Some gardeners apply a synthetic plant growth regulator, called NAA (naphthalene acetic acid), to suckers after pruning to prevent them from re-sprouting.



To develop a large shrub:

If an intermediate size of shrub is desired, prune moderately by removing the twiggy growth smaller than pencil size. This annual pruning will stimulate more vigorous growth in the spring.


To develop a bush:

I you prefer growing the Vitex or Chaste as a compact shrub instead of a tree, prune the stems back to approximately 12 to 18 inches above ground level each year. Severe pruning will not kill or injure a healthy plant. Prune before growth begins in the spring. The result will be an abundance of new flowering shoots.



Copy Provided courtesy of Star Nursery

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