A chaste tree (Vitex agnus-castus) can be grown as a large, multi-stemmed shrub or as a single-trunk tree. It grows 15 to 20 feet tall and wide. It is a deciduous tree that blooms in May and June with lavender, purple, pink or white flowers. A chaste tree blooms on the current season’s growth. Prune the tree while it is dormant, usually in December to early March, to encourage new growth and more blooms.
Remove any damaged, diseased or dead limbs and branches. Use hand pruners for limbs up to ½ inch in diameter and lopping shears for larger branches. Make pruning cuts at a 30-degree angle at a bud or where the affected limb meets a larger limb or branch.
Use hand pruners or lopping shears to remove any crooked, bent or crossed limbs.
Thin the older branches of a shrub-style chaste tree by cutting them at ground level with hand pruners or lopping shears. This will encourage healthy new limbs to grow in the spring.
Remove any limbs that are too low on a non-shrub chaste tree. Prune them as close as possible to the main trunk without cutting into the main trunk.
Shorten individual limbs and branches with hand pruners or lopping shears to shape the plant and maintain its size.