Trees and shrubs are the landscape plants that form the "backbone" of your yard's vegetation. You'll often hear this statement, and what it refers to are the size and permanence of trees and shrubs. Trees can take a dominant position over the rest of your landscaping by reaching vast heights, while both trees and shrubs are "woody" landscape plants that don't desert us in the winter. But to "flesh out" the skeleton, if you will, provided by trees and shrubs, you'll want to grow some low-lying landscape plants, as well.