Fast growing trees are desirable for their ability to quickly cast shade, provide a screening barrier, form a hedge or simply as a beautiful focal point in a landscape or garden. Unfortunately, the ability to grow quickly is not always a positive trait in a tree. Many fast growing trees have problems that are a direct result of their rapid growth rates.
Fast growing trees often have brittle or weak wood, according to Wayne K. Clatterbuck, a professor of forestry at the University of Tennessee. These trees have branches that may break during windstorms or ice storms. Often, the breakage occurs at the point where the branch meets the trunk. Not only will detract from the appearance of the tree, but these kinds of injuries are typically difficult for trees to recover from.
Another downfall of fast growing trees is that they are often short-lived. This is especially true in the case of deciduous shade trees and in certain species such as the leyland cypress. While they may quickly grow large enough to provide shade or a barrier, these trees will also reach their peak around age 25 and then begin to weaken or die.
Fast-growing trees can get very large very quickly. Some will grow so tall and narrow that the branches will start to "peel away" from the tree as they succumb to gravity. Again, the leyland cypress is one that suffers from this problem. The roots of the tree may spread and buckle sidewalks or driveways, or creep into a neighbor's yard, as might the canopy of the tree. Fast growing trees often collide with overhead power lines or underground water pipes. They can quickly become too large to manage and maintain.
Certain species of fast growing trees can suffer from other common problems as well. The state tree of Tennessee, the yellow poplar, is a fast growing tree that is very susceptible to heavy rains. The American sycamore tree is susceptible to anthracnose, a disease that causes the tree to rapidly decline. The eastern cottonwood, one of the fastest growing trees in America, has extremely shallow roots, which means it topples over in windstorms very easily. The cottonwood also tends to lose its leaves in late summer rather than the fall, making it not very useful as a shade tree.