Pruning Young Trees
By Kay DiVerde
Trees do not grow into big beautiful shade providers with just luck. And the time you spend training your young trees during their first 4-5 years of life will be worth every minute later on. And when/if you need to pay to have a large mature tree pruned to correct a problem, it can be very expensive, and the pruning wounds heal much slower. Pruning trees when they are younger is easier on you AND the trees.
Before starting to train and prune a young tree, think about how you want it to look as a mature tree. If you are not familiar with the variety, consult a tree encyclopedia to determine the tree’s natural shape and expected growth outcome. If you don’t like the tree’s natural shape and/or have space restrictions, now is the time to make some decisions. In addition to being familiar with the tree’s natural shape, it’s also a good idea to find out if your variety has any special shaping needs. If you know what your ultimate goal will be, you will know how to start pruning your young tree. Young trees respond better to pruning than mature trees, so during the early years is the time to get them into the shape you want.
If limbs are broken or damaged while bringing the tree home from the nursery, prune them right away. Cut close to the trunk and outside the branch collar. During your tree’s first year, don’t do much pruning other than to remove diseased, damaged or dead wood.
As with all pruning, you need to remove any broken branches. Broken areas are where insects and disease can enter the tree. Suckers that start around the base of the tree also need to be dug up and removed. Water sprouts that attach to limbs also should be cut off. They just tend to grow into weak wood.
During your tree’s second year is the time to develop a strong central leader. This is the main trunk of the tree from which the other branches grow. You can use thinning cuts to remove all but the most central, strongest and most vigorous of the upright-growing branches. While some trees may end up with multiple leaders as they mature, training a young tree to have one central leader will give it the sturdiest branching structure possible.
You can start the development of the scaffold branches during the tree’s third or fourth year. These branches will create the framework of the tree. Spacing is the key to working on scaffolds. For vertical spacing strive for three percent of the tree’s mature height. Pick the limbs that you find evenly distributed around the trunk. You don’t want them to be too close to each other, and directly above one another is not good. Have the scaffolding branches be no less than six feet off the ground. This will allow most people to easily walk underneath them.
Along with spacing, another important consideration is the angles at which limbs join the trunk. You’ll get a stronger attachment, when the trunk and branches join at wider angles. You need to avoid angles which are narrower than 45 degrees. Think of the framework of your tree like a clock. The trunk is at 12:00. You also want limbs at 2:00 and 10:00. Some trees with an upright form will have a different framework pattern. When checking angles, be sure to remove branches that cross over branches or rub against them.
When choosing limbs to keep for the scaffolding, check the diameter of the limbs. The scaffolding branches need to be smaller than the trunk in diameter. This smaller size will end up being stronger and not as likely to split from the trunk.
With a young tree, be careful not to prune too much - even if your tree has limbs low on the trunk and more growth on the bottom than on the top. The leaves on the lower limbs can help the trunk grow thicker, and they keep the sun off the trunk. Do trim back the lower limbs if they make an obstacle for walking around. Try not to remove these lower branches until they are at least one inch in diameter. As a general rule, raise the crown of the tree by cutting off one-third of the lower branches each year in late winter for three years.
No matter what age your trees are, the best thing you can do for them is to always prune with quality tools and sharp blades to avoid ragged or torn bark. With a sharp blade, you can make a nice clean cut that heals quickly and helps prevent disease. Once you start with quality products, keep them sharp and clean to maintain maximum performance.
Pruning young trees is like teaching young children. Start training them when they are young, and they’ll grow to be beautiful and healthy when mature. Decide what you want your tree to look like when it’s mature. Work to establish a central leader and get a good framework of branches. Watch the spacing and angles of the branches. If you do a little at a time when your trees are young, they’ll heal the fastest and require less pruning maintenance when mature.
Kay DiVerde is a freelance writer, horticultural researcher and consultant for Orchard's Edge. DiVerde also writes for a variety of newsletters and publications in the Midwest.
