March 20, 2002
Woodbury Bulletin
Betsy Halden

Choosing the right tree or shrub for the right site

As the days grow longer and the sun climbs higher, gardeners look at their yards and gardens and think about new trees and shrubs to plant. Choosing the right plant for the right place and purpose adds greatly to the sustainability of a landscape. Before purchasing a new plant there are some issues to consider. Here are some questions to ask in order to select the right plant for the right location.

1. What effect or purpose am I hoping to achieve with this plant? Is it to add texture or contrast, for shade, attracting birds, for screening or fencing, for fall color, flowers, or fruit? Be sure your selection will fill the intended needs. A windbreak specimen that loses its leaves in the winter may not provide much from the wind. Consider the plant’s ultimate size and shape, foliage type, and root system. Will the plant be too large, too small, too open, or too dense? Be sure to consider how it will look from inside the house as well as from outside.

2. What size plant is required? In general, trees fall into three size categories: large, medium, small. Large trees are 40 – 100 feet tall at maturity and dominate the landscape. They need to fit into the scale of existing plantings and buildings. Large trees are often selected for shading houses or creating a focal point in the landscape. Medium trees are 30 – 50 feet tall and are used for street tree plantings, shading lawns, and terraces, and where large trees would be out of scale. Small trees are up to 25 feet tall and are used where space is limited. They are selected for their special characteristics such as foliage or flowers, shape or form, and are often planted as a contrast to the background buildings or plantings.

Shrubs can be divided into four main groups: Fingertip high, 7 feet or higher; head high, 5 – 6 1/2 feet; knee high, 1 1/2 – 2 feet high. However, you may find shrubs on a spectrum anywhere from 4 inches to over 10 feet high.

Width is also an issue to consider. Shrubs come in different shapes: upright/columnar, spreading, rounded, and vase-shaped. Most shrubs can be pruned to a desired shape and size, but they will look better and require lass work if they are pruned to enhance the natural shape. Shrubs are used to separate areas, define spaces, and create contrast.

3. Is the plant I have selected able to grow well on my site? What is the soil type, drainage, exposure? Is the plant hardy for our Zone 3 – 4 climate? Does it have special growth requirements such as soil pH, partial shade, well-drained soil, or protection from the wind?

4. Will there be sufficient space for the plant on this site when it reaches maturity? Allow sufficient space from the house and from other nearby plantings. Base your spacing on the mature sizes of the trees and shrubs to avoid problems later. Consider getting the largest specimen affordable to help reduce time to maturity and to better estimate spacing. If smaller specimen are planted fill in with perennials or bulbs which can be removed or relocated as the plants increase in size. Will the plant obscure walls, windows, or doors when fully grown? Will it crowd sidewalks or fences? Is it going to situated under overhanging roof gutters? a quick walk or drive through your town or neighborhood will make very obvious the need not to overlook this step.

5. How much maintenance will be required to keep the plant attractive and healthy? Do I have the time, equipment, and knowledge to do what is required? Are there disease or insect problems? If so, are there resistant cultivars to plant? Will the plants need to be watered regularly? How much pruning is required? Is it a tree that loses leaves, branches, nuts, cones, fruit, or other debris which has to be raked up and removed? Is there added expense involved for special site preparation, fertilization, or pesticide application?

6. Does the plant I have selected pose hazards? Are the plant parts poisonous to children or domestic animals? Will thorns or briars pose a problem? Does the plant have a disagreeable odor while flowering? Am I planting a tree too near the house that is susceptible to wind throw, splitting, or losing large branches?

For additional information and suggestions for choosing the right plant for the right site go to www.sustland.umn.edu. The site offers information on woody and herbaceous plants for our area. You will be asked to give characteristics of plants you would like to find. This is a great site!

Travel tip: If you are planning a trip to Orlando this spring and plan to visit Epcot, notice the gardens near each nation’s exhibit. The designs and gardens include plants that are indigenous to the each country.

Betsy Halden is a resident of Woodbury. University of Minnesota Extension Service and Iowa State University Extension Service materials were consulted in the preparation of this column. You can reach Betsy Halden at eahalden@comcast.net.