The best time to prune a Mulberry tree is in the dormant season when there are no leaves on the tree. There are two exceptions to this. First in case of safety issues, if the tree is blocking your vision of a street sign. The second is for health reasons. There may be a diseased branch that has to be removed.
There are two types of pruning techniques commonly used on Mulberry trees. The first is called crown reduction. Crown reduction is the shortening of branches by pruning the leader back to the length of healthy, vibrant secondary branches and allowing them to become the new leader branches. This strengthens the somewhat weak wood of Mulberry trees. This technique involves reducing the top, sides and individual branches in this manner.
The second technique is called pollarding. This should be started when the tree is still quite young and the branches small. Mulberry is prone to bleeding. Cuts over 2” in diameter should be avoided because they will most likely not heal. This will also leave your tree susceptible to fungi and disease.
Pollarding cuts should be completed before the buds start to open and show color. Only the slightest bit of branch should be left to form a knuckle. This should be repeated every 2 years. Each time remove the new growth to the knuckle but leave the swollen area. Latent buds will sprout from this knuckle.
This is not the healthiest way to prune a tree but Mulberry trees can thrive under this type of care for years. Pollarding was originally done as a way of keeping trees small. If your tree has already been pruned this way you must continue it.
The above two pruning techniques actually shorten the life span of your tree. They drain the tree of it’s energy and strength. It will spend more time trying to replace the foliage that was cut. It will starve and become weakened by being deprived of the food that was in the leaves.
Mulberry trees do not require special pruning techniques. The following gentle tips can be used on any tree as well as the Mulberry. They will produce a much healthier tree when followed.
• First remove any diseased, broken or dead branches.
• You should never remove more than 1/3 of your tree’s leaves at a time. You should wait until the next year to remove any more than this.
• Try to make as few cuts as possible. Use cuts to guide the shape of the tree. You should carefully examine the tree to determine which branches you will cut. It should only require about 5 main cuts to prune a healthy tree. Plan ahead and visualize before making any cut.
• When cutting a branch always cut back to a branch that is at least 1/3 the diameter of the branch to be cut. The energy from the branch that was removed will now be transferred to the branch at the cut.
• Think about the natural shape of trees. About 2/3 of the trees leaf canopy should be below the top. Many people make the mistake of removing to much new growth from the bottom and the tree ends up looking like a top heavy beach umbrella. This makes the tree more susceptible to wind damage and it may get blown over in a storm.
Pruning a Mulberry tree is not difficult. One last bit of advice is to know the purpose of each cut beforehand. Trees are pruned for different reasons. Is it for increased fruit production, to control the size or to maintain it’s health? Careful preparation before making any cut is the key to successful, healthy, maintained Mulberry trees.
Photo by smarkflea, Creative Commons Attribution License