The new July 2009 issue of Southern Living features an incredibly entertaining and informative story written by me about three great trees for summer blooms. In case you're too cheap to buy it, let me discuss my favorite tree of the bunch -- chaste tree (Vitex agnus-castus).
Native to southern Europe and central Asia, chaste tree quickly grows into a multi-trunked tree about 10 to 20 feet tall and wide with a broad, spreading habit. It gets its name from the erroneous medieval belief that a potion made from it could curb the libido. In reality, wearing a house dress with orthopedic shoes and multiple nose piercings is much more effective.
That doesn't mean that chaste tree doesn't have its pharmacological uses. An extract made from Vitex supposedly does a very good job of controlling PMS. Which means any of you guys out there who are routinely beaten every 28 days should definitely plant one in the yard.
Blue for You
But the best thing about chaste tree, in my uber-learned opinion, is the flowers. Chaste tree is one of the very few winter-hardy trees out there that sports true blue flowers (although they can also be pink, purple, or white). The one you're looking at here is 'Abbeville Blue.' which bears large, spectacular panicles of deep-blue flowers in summer. Other selections I like include 'Montrose Purple' (purple blooms), 'Shoal Creek' (blue-violet), and 'Silver Spires.' (white). If you buy an unnamed chaste tree tree from a nursery, buy it in bloom so you can see the color of the flowers and the general shape of the plant. A good mail-order source for named selections is Forest Farm.
The Skinny on Chaste Tree
Here are some different ways to use chaste tree in the landscape:
1. As a single specimen in the lawn
2. In a row along a property line or a driveway
3. Limbed-up in a border with lower plants growing beneath it
4. As a small patio tree
Few trees are as easy to grow. Here's the low-down:
Light: Full sun
Water; Regular moisture at first -- very drought tolerant once established
Pests: None serious
Pruning: Not the tidiest plant in the world. Needs regular pruning to produce an attractive multi-trunked tree. Prune in winter. Clean out the entire center of the tree, removing all side branches from main 4 to 5 trunks. Also remove messy, twiggy growth that tends to crowd the ends of the branches. As an option, cut entire plant to ground in winter. It will sprout in spring and bloom in summer, although later than chaste trees not pruned so severely. You can also force a second bloom in summer by removing the first flush of blooms as soon as they fade.
Salt & wind tolerance: Good
Cold-hardiness: Winter-hardy through Zone 6; in Zone 5, may be killed to the ground in winter, but will sprout and bloom the following summer.
Bee alert: Bumblebees love this plant above all others and will even spend the night on the flowers. Keep this in mind if bees freak you out.