I was at an outdoor gathering last week and someone asked me the name of a small tree with lavender flowers that looked similar to a butterfly bush. The plant is a chaste tree, also called Vitex (Vitex Agnus-Castus). This drought-tolerant, pest-free plant is a great alternative to a crape myrtle for summer flowering.
Chaste tree is a favorite of many Southern gardeners. Its berries are mentioned as far back as Roman times. The early American nurseryman Peter Henderson said Vitex has been cultivated in the South since 1670. It became somewhat uncommon in gardening circles for many years, but it is enjoying a rebirth. It was named the 2001 Georgia Gold Medal tree. Gold Medal plants are selected by a group of professionals in horticulture for their ability to grow and thrive in Georgia's climate.
The chaste tree, also known as lilac chaste tree, sage tree or Indian spice, is also found in Southern Europe, China and India. For folks in the warmer part of the South, like Augusta, the lilac chaste tree has been the shrub of choice to mimic lilacs, which many Northerners come to realize will not grow in the Augusta area.
Chaste tree is a fast-growing, multiple stemmed tree tree attains a height of 15 to 20 feet with an equal spread, but it can be controlled with early spring pruning to the desired size. It can be cut to the ground each spring and will regrow from its roots, if you are concerned about size. If planted in the spring, a one-gallon size plant can be expected to reach 6 to 8 feet by the end of the growing season. And it will bloom the first year.
Chaste tree prefers full sun and can tolerate most soil types, including dry, poor soils. Try to avoid poorly drained soils.
Like many members of the Vervain family, chaste tree attracts butterflies and bees. In fact, it may be undesirable to place the tree near high traffic areas because of the bee activity when the tree flowers.
Chaste tree has opposite and palmately compound leaves with five to seven leaflets. The foliage is gray-green in color and very aromatic when crushed. The tree is deciduous and good fall color is not one of its attributes.
The most outstanding feature is its fragrant blooms, which appear from May through July on new wood. The cool lavender color is an unusual and somewhat difficult color to find in our gardens during the hottest time of the year. Individual blooms are tiny, about 1/4 inch, but they are borne in masses on large, multi-branched panicles, much like crape myrtle and butterfly bush.
Chaste tree can be an asset to any landscape when properly used. Because of its size and openness, it should not be used as either a foundation plant or screen. The best utilization would be as a specimen tree in either a patio area -- where its lacey foliage will impart a feeling of airiness -- or in the yard away from the house. An excellent place would be to make a statement at the street at the entrance of a driveway.
You can take advantage of chaste tree's gray foliage by planting contrasting red flowering annuals in spring. Marigolds match well with the chaste tree's distinctive lavender flowers. Use your imagination in creating combinations.
For different flower colors, other cultivars of chaste tree include alba or silver spire with white flowers, rosea with pink flowers and abbeville blue with deep blue flowers. Shoal creek and lilac queen sport the lavender or blue-violet flowers. Vitex negundo is very similar to Vitex agnus-castus except that the flowers are not as showy and it is larger.
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. Pruning in July will result in a second floral display by October.
As previously mentioned, one of the best qualities of chaste tree is that they are basically pest free. On rare occasions, flea beetles can be an early spring problem.
Chaste tree is basically a short-lived tree, beginning to decline after about 20 years, but so do many other plants, such as dogwoods (at around 25). That should not prevent you from enjoying it for many years.
REACH SID MULLIS, THE DIRECTOR OF THE UNIVERSITY OF GEORGIA EXTENSION SERVICE OFFICE FOR RICHMOND COUNTY, AT (706) 821-2349 OR SMULLIS@UGA.EDU.