GV?Gardeners: Is there a Vitex in your future?

Vitex (Vitex agnus-castus), a lovely summer flowering tree, has been traced to the time of Hippocrates, 2,500 years ago.

Over the generations, this native of India and Southern Europe has been given a number of common names: Lilac Chaste Tree, Hemp Tree, Sage Tree, Indian Spice Tree and Monks’ Pepper Tree. Here in the desert, it is most likely called Vitex or Chaste Tree.

The Monks’ Pepper and Chaste Tree names originated because of a medieval belief that drinking potions made from the berries helped monks maintain their vows of celibacy. The tea is said to lower libido in men, and help with PMS symptoms in women. Modern European doctors support this historical wisdom by using Vitex berry preparations for various menstrual and fertility disorders.

In the Green Valley area, this deciduous tree is in bloom now through September, with its long vertical flower spikes covering the tree. Shaped much like the flower of lilac bushes, its colors can be lilac-blue, pink, or near-white. Spikes are 8 to 12 inches long, and if cut off as soon as the flowers fade, the tree will bloom again. It is known as a lilac replacement where it is too warm for lilacs to grow, such as in the Sonoran desert.

The Vitex is really a multi-trunked shrub, growing upright and rounded much like the crape myrtle. To develop into tree form, it must be pruned, or “limbed up.” Growing to a mature height and spread of 10 to 25 feet, it can be reduced by up to one-third when dormant in winter to control size and to maintain branch density.

While talking of pruning, if a Vitex is cut down, be certain to promptly get out all of the stump and as many roots as possible. Otherwise, dozens of vigorous branches will grow from any basal roots remaining.

At the Arid Garden, it was necessary to remove a Vitex tree on the south slope several years ago, leaving the small stump in place. Now visitors will jokingly ask if the garden is growing marijuana (which Vitex leaves closely resemble). Fresh green leaves grow from the stump nearly overnight. It is necessary to keep trimming away the new growth or soon there would be another Vitex where it is not wanted!

Planting is recommended for spring, in full sun to encourage more abundant and colorful flowering. The first year, water every seven to 10 days. After established, water every 2-4 weeks in the growing season, and once or twice during winter. Fertilizer is unnecessary. Vitex is a sturdy tree not susceptible to pests or disease. It is cold hardy down to 15 degrees, and thrives in summer heat.

This tree also has desirable aromatic properties, so is used in aromatherapy. The dusky gray-green foliage has a pleasant, sage-like spicy scent. In addition, the small round seeds have a pungent scent (and flavor) much like black pepper. All of this plus the beautiful “faux lilac” flowers of summer make choosing Vitex easy.

There are several examples of various ages and sizes at the Arid Garden, off Camino Encanto. All have identification signs so are easy to find. Come for a look, and then decide if there is a Vitex in your future.

Mary Kidnocker is a Master Gardener who writes frequently about the subject from a local perspective. Her columns are featured Sundays. She is president of The Green Valley Gardeners.