Vitex Agnus castus was known since ancient times as Chaste Tree for its supposed anaphrodesiac qualities. Chaste Trees were brought to the colonies very early for their qualities as a medicinal herb. Their beauty in the garden and the ability to supply poles for beans and peas from their vigorous annual growth.
Vitex Agnus castus is an improved selection of Vitex negundo. It has been selected over many years for its larger more colorful flowers. Both are equally attractive to bees though Vitex negundo is said to be slightly hardier. Both are vigorous growers and produce their abundant flowers on the current seasons growth.
Vitex is hardy in zones 6 to 10. In zone 5 it may be possible to grow as a tender perennial in a protected spot. Even in zone 6 it should be cut to the ground each fall and grown as a shrub. Because of its rapid growth , Vitex is an effective summer blooming shrub even when managed this way.
Farther south, Vitex can be a large shrub or it can be pruned to a single or multi-stemmed small tree. It can be a shrub of 3 feet or a tree of 15 feet depending on the needs of the gardener. This versatility of form means Vitex can be used in almost any landscape. Vitex makes an effective hedge and as such is a very effective bee forage.
Vitex produces a profusion of flower spikes in mid summer when most plants are suffering from summer heat. Blooming persists on new growth until frost each year. This long bloom period is important to honeybees and other pollinators for both the volume of flowers and the season they open.
Vitex is a tough, drought resistant plant that does well into the southwest. Beekeepers across the south report that Vitex is an important pollen and nectar source for their long hot summers.