Selecting the Right Tree or Shrub
Options and Selection
Selecting trees and shrubs is an exciting way to translate your ideas into reality, so make sure they’re the right ones for your landscape and site.
An important consideration in choosing trees and shrubs is whether they are hardy in your area—that is, whether the plant will thrive for many years in your garden, barely hang on, or fail to survive.
To a large degree, hardiness is determined by the averaging of extreme low temperatures over many years. The primary guide to plant hardiness is the USDA Plant Hardiness Zone map [See: Plant Hardiness Around the World, on this page].
Consider two examples: A camellia that is hardy in warm-climate Georgia may do poorly in cold-winter Alberta. Blue spruce are a species that grows well in the high Rockies and Canada, but is a poor performer in Florida, where high summer temperatures are the norm. Choosing the right hardiness is vital.
You’ll want to consider other factors as well. Those who live in arid regions should select plants adapted to hot and dry conditions. If you garden in a coastal area, choose plants adapted to sandy soils and saline breezes.
Local nursery and garden center staff and university extension service agents provide helpful information about these issues. You’ll also find it clearly stated in the trees and shrubs index [See Ornamental Trees].
Climate and Microclimates
After considering your climate, think about the microclimate in which you plan to place your trees or shrubs. Climate is a big picture view, while microclimates are like looking at the pixels that make up the pictures on your device.
Every yard or patio, no matter how small, has microclimates—areas that are a few degrees warmer or cooler than their general surroundings, or areas that are more windy or more protected than others. Your yard may be warmer or cooler—sometimes a great deal—than your neighbor across the street or down the block.
You can use these microclimates to good advantage. Shrubs and trees that bear tender blooms in early spring can be protected from late frosts when they are planted in sheltered spots.
By contrast, you can encourage early bloom on flowering trees and shrubs by setting them in a location with early warm sun and protection from wind exposure.
Determine the microclimates in your yard by observation and by asking your neighbors what luck they’ve had with tender plants.
After a light snow, the spots that melt first are in warm microclimates; Drifts and ice linger longer in shady, cold spots.
Gardeners in mild-winter climates can also note which parts of the garden have the first spring growth. Blooms from the same species may be weeks or even months apart depending on microclimate considerations.
Locations nearest a structure are typically a few degrees warmer than exposed areas, and low spots tend to be colder than high areas.
Climates and Plant Hardiness
U.S.D.A. Plant Hardiness Around the World
The United States Department of Agriculture (U.S.D.A.) divides North America and other areas of the world into 11 plant hardiness zones.
The U.S.D.A. Hardiness Zones, based on long-term extreme minimum annual temperatures, serve as a general guide to growing conditions.
Trees and shrubs are rated as to the zones for which they are best adapted—for example, zones 4–7—and these are usually listed on plant labels and in plant encyclopedias [See: Ornamental Trees].