THE QUESTION OF HARDINESS

We are constantly asked if a tree is hardy, with the implication that hardiness guarantees that the tree will survive in our climate. This is not the case.

We as nursery growers can recommend plant material that should be suitable for our climate but the ultimate survival of the plant depends on a number of other factors. Local climate, soil type and fertility, availability of moisture and the length of the growing season are all factors that directly affect the survivability of plant material. These factors vary with each planting location. It is therefore impossible to state that a plant will be 100% hardy for any large area such as the prairies.

Besides these cultural needs of plants another consideration is the human factor. Plants suffer from the human factor in two ways, either they are under cared for or over cared for.

Although most plants will survive on their own once they are established, a critical period for a plant is that time between when it is purchased from a nursery until it is well established in its new location. Many mistakes are made in handling plants during this time. They are often over or under watered. The roots are exposed to the air for prolonged periods. Plants often fall victim to the theory that if they need a little fertilizer then a lot will be better. When over fertilized the hair roots that are required to establish the plant are burnt off. The plant must struggle to redevelop these roots before it can begin to grow and establish a new root system to anchor itself in its new location. Often at the same time the plant sits in a pool of water and drowns. Over applications of fertilizers and water can also force plants to grow too long in the fall and expose tender growth to the first hard frosts of winter. The damage done at this time is most often irreversible and results in winterkill on the stems of the plant.

We seem to feel that we need to control plant growth and assume that we can do a better job than Mother Nature. This excessive care often has the most devastating effect on the well-being of plants.

Hardiness - as in plant survivability - is dependent on so much more than plant genetics. Keep these thoughts in mind when you purchase your trees. You should find out if a plant has been successfully grown in an area similar to yours, but don't take that as a guarantee that it will survive on your site. The conditions in which it is planted and the care it is given are the factors which will determine a plant's survival.

Amanda Chedzoy

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