History and Horticulture: Vitex agnus-castus

This is a plant with an interesting background. The common name chaste-tree should clue you into some of the folklore around this plant. Ancient Greeks, Romans, and medieval monks all believed that the berries would keep their thoughts pure. It also has a long history of being used as a herbal treatment for a number of women’s health issues. 

More recently, it has been valued simply as an ornamental shrub, especially in warmer climates. If you’re in a southern climate where lilacs don’t do well, perhaps give chaste-tree a try; the flower color is quite similar.

Blue Diddley® is a compact version of chaste-tree. While traditional varieties can get large and even grow to be small trees (up to around 20 feet tall), Blue Diddley® maxes out at about 6′.

In colder climates, Vitex agnus-castus is like Buddleia and behaves more like a perennial. It’s considered hardy to USDA Zone 5 as a dieback shrub and will be a shrub in Zones 7-9. What about Zone 6? Well, it will depend on the winter. You can check with your local extension service to see if it’s suitable for your area.

Either way, it’s an interesting addition to a sunny bed or border. Just make sure the soil is well-drained, and you can enjoy this cute little ball of blue flower spikes in summer. Blue Diddley® also has pretty good deer resistance and salt tolerance.

Are you a fan of blue flowers? 

People seem to be obsessed with blue flowers. Maybe it’s because the color is associated with peace, tranquility, and stability or because blue is rare in the botanical world. Actually, blue is quite rare in all of nature. 

Yet we want blue hydrangeas, roses, etc. Well, if you’re a lover of blue plants, you’re in luck! We have plenty of blue shrubs that can fit into just about any garden; just check out some of the options in the video below!