If you have a small patio, large sugar maple or towering oak will not fit. Fortunately, there are many small trees that can be planted in your yard or garden. In fact, many trees were grown for smaller spaces. When buying, check the estimated heights of the trees and look for shorter varieties. Those with the word "dwarf" in their names tend to be shorter, like weeping trees or trees with fallen branches. And always make sure it can withstand winters in your USDA hardiness zone. After…