When ME Contracting approached CLC Tree Services to write a guest blog for them, we were thrilled. We love to talk trees, so it’s only natural to want to share a little more about them. Not all trees are created equal though. When it comes to planting a tree, you need to consider several factors, not least of which is whether or not the tree is native to your area. There are usually plenty of trees to choose from, but selecting a native species should be your first choice.
Why Choose Native?
Get in the Zone
Native tree species are the natural choice for any new tree plantings for many reasons. When you select a native tree, one of the benefits is that it is naturally acclimatized to your hardiness zone. While CLC Tree Services is located in London, ON, in zone 6a, Toronto is generally designated as zone 6b (the difference between a and b is approximately 5°C). Even within that zone, microclimates can exist, depending upon your proximity to bodies of water, (the Great Lakes affect climate in a big way) and the degree of sheltering your property may have. The higher the number, the warmer the zone.
Why does your zone matter?
In Canada, the hardiness zones denote many things; lowest mean temperature of the coldest month, highest mean temperature of the warmest month, number of frost free days, amount of summer rain, snow cover, wind speed, and more. Ultimately, they dictate your plant’s chances of survival. A plant rated for zone 7b would have a hard time surviving in the harsher climate of zone 4a. Unless you plan to bring that specimen in for the winter, either pass it by when looking for something to plant, or consider it an annual and enjoy it for only one season. Plants that naturally grow in your zone are used to its climate, therefore have a better chance of surviving the temperatures, precipitation levels, and other variables.
Aside from being able to tolerate the climate, choosing a native species also benefits the wildlife in your area. While anything can perch on whichever tree branch is handy, there are certain birds, insects, and other animals that have developed a dependence on specific plant species. A great example of this is monarchs, which feed exclusively on milkweed.
Introducing a non-native species often offers little benefits to the native wildlife that depends upon it—everything from insects, to the birds and mammals who eat them. Many insects rely on specific food sources and if they cease to exist, their absence ricochets up the food chain. When native species have to work harder to find homes and food sources for themselves and their young, it hurts all life. A non-native tree species might as well not exist for the creatures who depend upon native trees.
Say No to Invaders
Another reason to plant native species has to do with the threat that some non-native species pose. When a non-native species is introduced, a host of problems can ensue, from crowding out native species, to having no natural predators to keep it in check.
An example of this in Ontario is the invasive common buckthorn. Introduced from Eurasia as a hedgerow and ornamental shrub in the 1880s, buckthorn has spread aggressively since then. Buckthorn forms dense thickets, which edge out native species, alters pH levels in soil, and hosts insects and fungi that damage local crops. Invasive species can cause extensive damage to local biospheres and cost hundreds of thousands of dollars to fight. While something might look pretty in a nursery, the ensuing damage to our ecosystem has the potential to be devastating and not worth the price tag.
You should also factor in that a non-native species has a harder time surviving. When less than ideal conditions occur, plants often require more care, for example more frequent watering and/or fertilizing. A tree that struggles is also more prone to disease and insect infestation, again increasing care costs. Why accept those risks when a tree grown close to home already has a better chance at survival?
So while you should always consider your soil type, amount of precipitation, and sunshine your area receives, not to mention personal preference, stick to native species when it comes to final decisions. There are plenty to choose from in a wide variety of shapes, sizes, and colours. The best part though is knowing that selecting a native species improves the chances that your tree will survive and thrive, providing you with plenty of benefits for years to come.