Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Planting
When deciding where to locate a Chaste Tree (Vitex), choose a site that provides well-drained, slightly damp to moist soil and full to mostly sun. The plant won't bloom as well if there is too much shade.

To plant, dig a hole no deeper than the root ball and two to three times the width of the root ball and fill it with water. If the hole drains within a few hours, you have good drainage. If the water is still standing 12 hours later, improve the drainage in your bed, perhaps by establishing a raised bed. Turn and break up the soil removed from the planting hole. If the native soil removed from the planting hole is compacted or heavy clay, mix in organic compost at a 25 to 30% ratio to condition soil. Remove your plant from its container and carefully but firmly loosen the root ball. Set the plant into the hole you've prepared, making sure the top of the root ball is slightly above the soil level. Pull your backfill soil mixture around the root ball in the hole, tamping as you go to remove air pockets. Then water thoroughly and cover with a one to two-inch layer of mulch.

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Pruning
Chaste Tree (Vitex) does not require pruning however it can be pruned in late winter and even during summer after the first flush of blooms has finished. Pruning at this time will often encourage a second round of blooms. Summer pruning should be lighter than late winter pruning. Late winter pruning is very similar to pruning crape myrtle trees.

See this article for detailed pruning instructions:

http://www.gardenality.com/Articles/344/How-To-Info/Pruning/How-To-Prune-A-Crape-Myrtle/default.html

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Feeding
Chaste Tree (Vitex) isn't a heavy feeder. I fertilize mine one time a year with a well-balanced shrub & tree type fertilizer after new growth begins to emerge in spring.

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Problems
I've had no pest or disease problems with the Chaste Tree (Vitex) growing in my landscape. Water occasional during prolonged periods of dry weather during summer.