Growth Rate: Many gardeners want to know how fast their plants will grow. A general guide of fast, moderate, or slow can help determine if a plant is right for a particular situation.
Mature Size: Two numbers are specified, such as 15 x 20. The first number represents the plant's mature height. The second number represents its width. Unless noted, these sizes are in feet and indicate the plant's mature size under typical growing conditions. Plant size can be highly variable depending on where and how the plant is grown.
Form: Knowing a plant's form - upright, spreading, mounding, or vase-shaped - can help you select a plant to fit the space and design you have in mind. This is especially important with trees.