Prune Mesquite in the Summer?

Q. I have a Mesquite tree that has gone wild. I had it trimmed a year ago and thought I could skip a year but no chance. It’s rubbing against the roof again. When is the best time to have them trimmed? Can I do it during the summer like in August?

Finding the right amount of water to give trees like mesquite so they don't overgrow can be a balancing act.

A. Let’s talk about its “wild growth” first. Mesquite trees, like most desert plants, are opportunists. When water is present, they grow like crazy. When water becomes limited, their growth slows down. If water really gets limited, they begin to drop their leaves. If water is even more limited for a longer period of time, then branches begin to die.

            It’s fun to see a Mesquite tree grow eight or 9 feet a year but this is also a signal it’s getting a lot of water. Put this to your advantage when it’s young by giving it frequent irrigations and large amounts of water. As the tree begins to reach a size that you prefer, the watering schedule should be restricted.

            When the tree reaches the size you like, then it becomes a balancing act; finding the right amount of water and applying it at the right time so that growth is not berserk but the tree still looks good.

            When the tree is the right size, cut back on how often it receives water but give it a large volume when you do water. This helps develop a deep root system.

            The trick is to determine when to irrigate next. Use the information I just gave you to determine that. When you see the tree begin to drop leaves or the canopy begins to thin, then give it its next watering.

            As for pruning, light pruning can be done anytime. Branches that are rubbing on the roof should be removed as soon as possible. But if you are pruning significantly and opening the tree for a lot more sunlight to penetrate into the interior, then do this during the winter.