WILL IT GROW IN MY YARD?

One of the most frustrating questions I get asked as a nursery grower is, "Is this plant hardy for my location?" Frustrating because I cannot possibly be familiar with everyone’s growing location. To help in this respect I use the Canadian plant Hardiness Map as a guideline, but it in itself creates another set of problems. The major factor that determined the zones was the lowest mean temperature for that area. Other factors were taken into consideration such as length of frost free period, moisture, winds etc., but the main determinant was temperature. The problem is that there can be many variations or microclimates occurring in each of these zones, and that the edges of the zones are very indefinite.

Microclimates are present either as natural phenomena, a body of water, hills, valleys etc., or are created by human intervention, such as plantings of trees, buildings, fences, or remodeling of the terrain. All of these factors can significantly affect the climate. Towns and cities with their mass of buildings and people can raise the temperature, therefore creating a micro climatic area, in which a larger range of plants may be grown. Planting on a hillside can be a quite different situation than planting at the bottom of the same hill.

Rather than show the map in this catalogue, I am including a list of the zones and their minimum temperatures. You can decide on the appropriateness of a plant by the minimum temperature that is relevant to your location.

Temperature is important but another factor is the amount of snow cover. Areas with low temperatures that have consistent good snow cover may be suitable for a wider range of plant material then might be indicated by the Plant Hardiness zones. An area prone to snow loss during the winter, such as when chinooks are prevalent, will accommodate a lesser variety of plants. It is possible to overcome some of these issues by mulching or other cultural practices.

Other factors that affect plant hardiness are soils and fertility, moisture availability and water quality. You may have a lovely growing location in respect to climate but be cursed with horrible heavy clay soil. Plants grown in this condition may be weak and not survive the winter because they are lacking the correct internal resources. With a little soil modification you may become a very successful grower. Conversely your soil may be very rich and cause plants to grow too vigorously into the fall and suffer frost damage during the first frosts of the fall. This is a common problem with Evans Cherry. Again you may be able to modify your soil to help prevent this from happening. Your ability to grow successfully may be affected by your ability to provide sufficient amounts of good quality water. Plants that receive insufficient water during the growing season are weakened going into the winter months and winter kill may result. Some well water contains too many minerals or salts to be used for watering plants. The water may impede the uptake of nutrients so plants are not in their healthiest condition going into winter.

Hardiness zones are not the end all of successful growing. They are simply a rough guideline to provide a starting point. You are the best judge of the area you wish to grow in. Look around your neighborhood and see what other plants are growing successfully. If you are in an area that is classed as zone 3 but you see a number of plants that are rated for zone 4, then try them. If you see nothing that is rated higher then zone 2 caution may be in order.

One of the most exciting aspects of gardening is testing the limits. It is very rewarding to be successful with a plant not considered hardy for your area. There are no guarantees that a specific plant will grow well in any area, it is dependent on the planting of suitable material, the environment and the gardener.

Amanda Chedzoy

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