Fact: Many people top trees because they fear a tree will get too big and drop limbs on their houses or vehicles. In realty, a tree which has been topped is much more likely to break apart and drop limbs than a tree which has retained its natural shape. There is no such thing as a tree that is "too big." Trees only get as large as they are genetically capable of getting.
Fact: Topping does stimulate growth, but the resulting rapid, weak growth is less desirable than normal growth experienced by a properly pruned tree. This type of damage also increases the chance that the tree will have insect and disease problems.
Fact: Topping may appear cheaper than pruning, but in reality it is quite expensive, and a waste of money. A poorly pruned tree will need more work sooner than a properly pruned tree. The true costs of topping include increased risk from dangerous and potentially hazardous trees, future maintenance to correct the damage, and loss of aesthetic value.
Fact: Tree pruning is both an art and a science. After you are done pruning a tree, it should barely look like it has been pruned. If you don't feel confident to prune small trees or if you need large trees pruned, consult an arborist! While topping is a problem which has plagued the tree care industry for years, it is also an opportunity to educate the public about the concepts of proper pruning and tree care.