River birch losing leaves is not a serious problem

Q: Can you help me figure out what’s likely going on with this river birch tree? The tree has been dropping leaves incessantly since about April/May, hundreds per day. Should this tree be dropping its leaves year-round? — Josh Chambers, email

A: River birches all lose leaves in the summer, some more than others. River birch is known as a “trashy” tree in that it drops twigs and leaves year-round. I don’t know which varieties are more prone to dropping things, but I’d bet the newer ones, like Heritage and Dura Heat, are less messy. Try watering more and see if that helps. For more information, see bit.ly/GAbirch

Q: I have two large, mature crape myrtle trees in mulched beds in my front yard. Unfortunately, they sucker mercilessly. Stems come up at the base of the trunks and several feet away. If I spray the suckers with Roundup, will I damage the trees? — Barry McCasland, email

A: Once upon a time, there was a beautiful allée of crape myrtle trees at the Atlanta Botanical Garden. The limbs curved over the long brick walkway wonderfully. Many a bride and groom were photographed at the entrance to the allée with the majestic crape myrtles framing them.

However, the Garden had a similar situation to yours: Unwanted suckers were emerging through the loose-laid brick pathway beneath the trees. One of the workers there, knowing how effective Roundup was at controlling vegetation, sprayed them with the herbicide. One by one, the beautiful white crape myrtles nearby turned brown and died. They were replaced at great expense. I predict the same thing will happen to your crape myrtles if you spray the suckers.

I have a huge crape myrtle in my front yard. It has rarely sent out root suckers, and it has never had trunk suckers in 35 years. NOTE: I have never pruned it. In my experience, pruning a crape myrtle can cause it to produce suckers as it attempts to balance the existing root mass with the reduced limb mass resulting from pruning.

The only thing you can do now is dig around the root suckers with a mattock to find the place where it attaches to a tree root. When found, prune as close to the root as you can without damaging it. Suckers attached at the base of the trunk should be cut out cleanly, as close to the trunk as possible.