Once they are mature, shade trees don't require much trimming, aside from the occasional removal of a dead or damaged branch. When they are young, however, shade trees need to be carefully pruned in order to ensure they develop a healthy and attractive shape when they are older.
The most crucial time in a young shade tree's life is between the ages of three and four. By this time, the tree has developed enough branches that it can tolerate you removing a few for shaping purposes. And so, when your shade tree is between the ages of 3 and 4, you will want to give it a good, solid trim. Here are the basic guidelines to adhere to as you do this.
Maintain a Single Leader
Some shade trees have an obvious single leader — a "branch" that stretches all of the way up from the trunk, and from which the other branches grow. Other trees may have a leader that splits partway up the tree. If your tree's leader splits, you will need to decide which side is stronger, and leave that side to keep growing. You'll prune away the other leader. This may leave your tree looking a bit unbalanced temporarily, but it will grow more branches and compensate. If you were to have left the split leader as it was, the branches would not grow as strongly as they should, and your tree would be more prone to split and broken branches as it continued to grow.
Remove the Lowest Branches
Make sure you cut off any suckers, which are sprouts that grow from low on the trunk. Also, trim away any branches that emerge from the lowest quarter of the tree. By removing these branches, you ensure that as the tree grows, its crown gets lifted off the ground, leaving space beneath the tree where you can walk and mow.
Remove Crossing Branches
Further up in the crown, look for any branches that cross each other. These will eventually rub together and damage each other as the tree grows larger, so it is best to just remove them now when they're small. Always remove the smaller, thinner, or weaker of the two branches that are interfering with one another.
If you follow the above guidelines as you prune your 3- or 4-year-old shade tree, you should be setting the tree up for a bright and attractive future.
If you have questions, contact a local tree pruning service.