Vitex - a Superstar for Texas Gardens
Looking for a plant to beat the summertime blue? How about a plant to give you the summertime blues – blue flowers that is? Vitex, a Texas Superstar, is starting its summer blooming bonanza, providing the welcome cooling effect of blue flowers just as the heat of summer arrives.
Vitex is also known as Lavender (or Lilac) Chaste Tree, Texas Lilac, and Monk’s Pepper, and 
has been also called Indian Spice, Hemp Tree, and others. Botanically, it is Vitex agnus-castus. By whatever name you call it, it is a great plant for Texas gardens. It has been in cultivation for centuries, in the U.S. since 1670, and is appreciated for its lovely lavender blue spikes of flowers. In ancient times, it was believed to aid monks in keeping their vows of chastity, and was also used for various herbal remedies.
Vitex is one tough and beautiful tree, a trait recognized by the Texas Department of Transportation which has planted Vitex in highway medians throughout Texas. There are a few of them in the center median on Interstate 20 west of Tyler on the way to Canton. Once established, Vitex is very drought tolerant, and will grow in all sorts of soil types, thriving in hot, dry and sunny conditions.
Recent work by horticulturists has made improved selections readily available through nurseries. Larger, more showy spikes of intense blue flowers on varieties like LeCompte, Montrose, and Shoal Creek (all sold as Texas Lilac or Vitex), attract butterflies like a magnet, making this a great focal plant for a butterfly garden.
Vitex is a fast grower, and will grow to be a very large shrub or small tree. If you want to keep it more compact, you can cut it to the ground every year. It is probably best grown as a multi-trunk shrub or tree, as occasionally an extremely hard freeze will take it to the ground, but will not kill it. Another desirable attribute of Vitex is that deer will not eat it.
Vitex blooms on new growth, beginning in early June, and the flower spikes will last for several weeks. They then set an abundant seed crop which stops production of new shoots. If you want a repeat bloom performance, simply prune off (deadhead) the spent flower stalks before they start forming seeds. This will push out a new flush of growth and flowers for a repeat performance. Of course, if you choose to grow Vitex as a tree, it will become difficult to deadhead as the plant grows taller. You can expect it grow 10 to 15 feet over the course of a few seasons.
There is a great specimen currently blooming in the center of the IDEA Garden in the Tyler Rose Garden. Master Gardeners who maintain the garden decided this year to compromise and not let it grow unrestrained and get too tall, but also did not want to cut it to the ground for the shrub effect. Rather, they cut it back halfway, leaving it looking a little gawky until the new growth hid the pruning cuts, and now the blooms grab all your attention.
Propagation is by cuttings in summer or winter. Lower limbs may be layered by burying in the ground while still attached to the tree, and there are sometimes volunteer seedlings that may be transplanted elsewhere in the garden. Typically the seedlings are of inferior quality to the mother tree.
Keith Hansen is Smith County Horticulturist with Texas AgriLife Extension Service. His web page is http://EastTexasGardening.tamu.edu His Blog is http://agrilifeblogs.tamu.edu/mt/etg Texas AgriLife Extension Service educational programs are open to all individuals without regard to race, color, sex, disability, religion, age or national origin.
