When choosing plants for your garden, you may opt for a tree or group of shrubs rather than a flowerbed, or you may decide on evergreens rather than deciduous trees and shrubs. Whatever your choice, one thing is certain, your final selection of trees and shrubs will have a long-lasting impact on the development of your garden.The successful integration of trees and shrubs into the rest of the garden depends upon them being compatible in both size and style. There is a tree for almost any garden, from small to large. When choosing a tree, don't pick something that will outgrow its situation. As a rule, trees in excess of 33 feet (10 m) are too large for most gardens and need too much maintenance.You should be aware of the spread of the roots of trees and shrubs, and plant them at a safe distance from your house and neighboring properties so as not to risk damaging the foundations of buildings or underground pipes.You should also consider the spread of a tree's branches as well as its height. Some trees grow as wide as they are tall and their spread may obscure too much of your outlook and create too much shade in a small garden. Trees that have oval, rounded and weeping shapes generally take up more space than those that are columnar, conical or pyramidal. With these things in mind, you'll be able to choose the right tree or shrub for your garden.