I have a lilac tree and a 3- to 4-inch branch just broke off. After I saw it off, should I brush or spray an ointment on the cut to prevent the tree from getting diseased?
The Gardener’s Answer
Before you prune out the branch that broke from your lilac, you will want to make sure that your cutting tools are sharp and clean. This will make it easier for you to make a clean cut and prevent any potential disease spread. You want to make your cut as close to the next intersecting branch or main trunk as possible but avoid cutting into the healthy wood. It is not recommended to cover or apply anything to the end of the cut. It is better for the tree to heal over on its own.
Annual maintenance will help lilacs in terms of vigor as well as overall appearance. Spring-flowering shrubs such as lilacs should be pruned immediately after they have finished blooming. Dead or diseased branches should be removed as soon as you notice them.
Lilacs will also benefit from being thinned, which means removing some of the older, woodier branches. This is especially true for the center of the plant, which can become dense and does not allow for good air circulation or filtered sunlight. Both can lead to disease problems.