As a rule, trees in North Florida can be pruned any time of year. However, the winter months seem to bring out the pruning bug in many folks. Also, any information on pruning would not be complete without a word on pruning crape myrtle. Read on for that information. Before we get out the pruning saw, loping shears, or pruning shears, there are a few things we need to go over.
Have an objective
First, you should always have an objective when pruning. You should have an idea why you are pruning so that you know when your objectives are met. Some common objectives include pruning for structural stability, reduce shade on lawns or ground covers, reduce wind resistance and aesthetic improvement.
Pruning is wounding
Second, you should remember that pruning cuts are wounds. When we prune a tree, we are setting in motion a wound response by the tree. This response is commonly called compartmentalization. The tree will try to wall off or compartmentalize any decay that will arise from the pruning. The compartmentalized tissue will be sealed off and become unusable to the tree. The wound response in the tree can be managed depending on the location and size of the pruning cut.
Location, location, location
This brings us to the third point, the location of the pruning cut. When pruning live branches, the pruning cut should be made just outside of the branch collar. The branch collar is the transition area between the branch and the trunk. By pruning just outside the branch collar, the wound response of the tree is minimized and less of the tree tissue is lost to compartmentalization. Also, the size of the pruning cut is smaller and can “callous’ faster when the cut is made just outside the branch collar.
Pruning paint is unnecessary
Fourth, pruning paint, tar, or varnish, is not needed. It has been proven to inhibit the tree’s natural healing process. In some cases, it can cause moisture to collect and increase the likelihood of decay. For further information on pruning from the University of Florida go to https://hort.ifas.ufl.edu/woody/pruning.shtml
Pruning Crape Myrtle
Now as promised a word or two on crape myrtle. In the past, it was true that you pruned crape myrtles to reduce powdery mildew infestations. With today’s resistant cultivars, crape myrtles require very little pruning. In fact, a crape myrtle planted in full sun with plenty of space to grow needs little to no pruning at all. There is no reason for the drastic pruning coined “crape murder” by many landscape professionals. While this type of pruning usually does not kill a tree, it is seen as extreme and unnecessary. To reduce the temptation of severe pruning select a crape myrtle variety out of the may selections that will have the mature height you desire.
If you find yourself in the position to prune crape myrtles, here are a few simple steps to follow.
- First, prune sucker sprouts and basal sprouts. If left to grow, these sprouts may form woody stems that eventually compete with existing main stems.
- Second, prune any rubbing or crossing branches, as well as dead branches. This may include branches that are crossing through the canopy from one side to another. As always make the pruning cuts at the branch collar.
- Third, (this one is optional) tip prune the branches to remove spent flower buds. This is also called pencil pruning because the branches removed are no thicker than a pencil. This type of pruning is the most labor intensive, but it also results in a more aesthetically attractive tree.
Recent research from Drs. Gilman and Knox at the University of Florida has demonstrated that the number of crape myrtle blooms decrease in direct correlation to the size of the branch removed. In other words, the larger the branch removed, the fewer the blooms. However, blooms on pruned trees were larger than blooms on un-pruned trees. To receive the benefit of larger flowers from pruning, prune just pencil sized branches without jeopardizing overall tree health caused by topping the tree. For more information refer to: https://edis.ifas.ufl.edu/pdffiles/EP/EP39900.pdf.