My tree has become so large I am afraid it might fall and do damage. How can I tell if should be shortened?
Large trees growing near homes and other structures can be dangerous during windy weather, especially if they have wounds, rot or weak branch connections. However, far too many healthy large trees are damaged by incorrect pruning. Simply reducing the height of a large tree does not necessarily make it safer. In fact, improper pruning can make a large tree even more dangerous.
Large trees such as fir, pine, maple, oak, and ash grow naturally to heights of 70 feet or more. With the exception of older poplar or cottonwood trees, they are not dangerous just because they have reached their normal mature size.
If you are concerned about wind damage to trees, the best way to prune them is to thin them by removing some of the inner branches so that wind can blow through the trees more readily. This practice is not recommended for large spruce and cypress trees, but it is for firs, pines and most deciduous trees. If there is good reason for reducing the height of large deciduous trees, they can usually be reduced up to 25 percent with proper pruning. A large branch can be shortened back to a side branch which is at least one third the size of the branch being shortened. This is sometimes called “drop crotch” pruning. The crotch is the point where two branches connect. If major branches are simply stubbed off at an arbitrary length without regard to side branches, severe damage can occur. If a weak or damaged branch does not have appropriate side branches, it is better to remove it completely back to its origin.
