What We Want and What Trees Need–Or Which Tree do I Buy?

By Cheryl Harrison, Master Gardener

We plant trees for various reasons. Trees are one of the main contributors to a beautiful landscape. They provide shade and can provide a windbreak. Trees sequester carbon and help to clean the air … some can even help to clean toxins from the soil. They serve as homes, shelters, and food for many birds and other small and large creatures including humans. A stroll through a forest can cool, calm, and inspire us!

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There is a lot to consider in order to choose the right tree for you.

Make a List:

Do you want shade, shelter, privacy or just something to fill a spot?
Do you want a tree that produces fruit or flowers?
Do you prefer leaves (deciduous trees) or needles (coniferous trees)? · Do you want a native tree? See Ontario Tree Atlas to see which trees are native to your area of Ontario.
Think about your budget. Some trees are more costly than others.

Location Considerations:

Stand in your chosen potential tree planting location and look around.

How close is your home and other buildings including the neighbour’s?
Are there any overhead wires that the tree’s branches will interfere with as it matures? Will the mature tree block window views?
Will mature tree roots eventually interfere with a building’s foundation or septic system? Will it’s branches scrape against walls, roofs or hang over the neighbour’s yard?
Will the tree drop fruit, seeds, twigs or large amounts of leaf debris on your sidewalk or deck?
How close are you to a road or parking area? Pavement impedes water and air from getting to the tree’s roots. Air pollution and road salt are very hard on many kinds of trees.

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Growing Conditions:

Next, lets look at what trees need. Different trees need different growing conditions.

Soil

Determine your soil’s texture. Sandy soil will not retain water or contain many nutrients. Clay soil has lots of nutrients but may not drain well. Silt soil may not drain at all. Most soils are a combination of sand, clay and silt and will benefit from the addition of organic matter. Seee Soil Types and Soil Texture for more information.
Test your soil’s pH, if very acid or very alkaline, it will affect a trees ability to access soil nutrients. There are home test kits available or you may send a soil sample to a soil testing laboratory in Ontario. See Soil Testing Laboratories List for more information.
Evaluate your subsoil especially if you live in a new subdivision. Newer subdivisions often have a thin layer of topsoil on compacted subsoil. You may need to replace some of the subsoil with topsoil or at least break the subsoil up so that the tree will not develop a shallow root system. A tree’s roots need to be able to spread out to access water and air.

See All About Soil for lots more information on soil.

Water

Water is necessary for the tree roots to absorb nutrients and for other life processes. Some trees prefer more water while others prefer a well drained site and there are lots of variations in between. How much moisture will be available to your tree?

Sun

Buildings, other structures and other trees can shade the soil. Many trees need full sun but many will tolerate partial shade. How much sunlight will your tree receive in a day?

Plant Hardiness Zone

The plant hardiness zone of your potential tree planting location will indicate the weather conditions that your tree needs. In Canada, the zones are based on maximum temperature, minimum temperature, rainfall, snowfall, frost free period and wind. See Plant Hardiness of Canada to figure out your plant hardiness zone.

“Which Tree do I Buy” Example:

You love trees that flower. You have decided to plant a tulip tree in the small courtyard of your condo in Peterborough, great, they grow in zones 3-4 … so far so good for the Peterborough area. However, tulip trees can grow over 35 m (115 ft) according to the University of Guelph, so a tulip tree is not a good choice for the tiny yard of a condo. The mature tree will be far too large!

In summary, make a list of what you want and your specific growing conditions. We have many locally owned plant nurseries nearby. The staff will use their expert knowledge to help you choose a tree appropriate for your needs and growing conditions.

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