Q: Last year my husband I planted a chaste tree. Somehow my husband did not keep it in check and now we are at a loss on how to prune it. My husband wants it to have three to four trunks similar to a crape myrtle. Do you have any suggestions?
My friend Rick Smith, The Pruning Guru, says:
“I have stared at these to pictures long and hard. There are 3 main trunks but the one that is lowest to the ground is the most undesirable. I would remove this one to the main trunk base. There is no need to treat the cut with anything after you make a cut. This slows down the healing process.
“Now you will have a lot of sucker growth and it can be used to your advantage. Since you have 2 main trunks remaining, you can pick the largest sucker limb at the base and train it to become the third trunk.
“The suckers that are growing around the bottom can be removed to clean up the appearance of the tree. Imagine where you would like the canopy to be and take trunk suckers off up to that point. From this point forward, you can remove every other sucker limb that is making up the top part of the tree and remove any crossing branches as well.
“To make the top to look better, you can lower the height of the suckers that are taller than the majority of the suckers or branches. When you prune these, lower them a 1/3rd in to the tree but make sure you stagger the cuts. This means when you lower them all of the cuts are not the same height as the others. Make sure where you prune them that you prune to a bud and make your cut in a angle. The angles needs to be sloping away from the bud and not toward the bud. This will help with water running off the new cut instead of standing on the cut if you made the cut straight across.
“Remember that vitex (chaste tree) blooms from new growth, so don’t be concerned about losing your blooms if you prune in spring
“When you prune, you are pruning for the future growth and beauty of a plant, so right now you are shaping this Vitex into a nice tree form.”