It’s not uncommon to think of tree roots as being large, heavy, powerful and potentially destructive. Misconceptions about trees, their roots and how they grow can lead to improper planting and maintenance, and even deter some people from planting a tree in their yard. Rather than fear tree roots, we need to protect them to keep our trees healthy and strong.
The roots at the base of a tree’s trunk are large and provide support, but these roots quickly decrease in size and diameter, becoming a series of fine feeder roots. Most of these feeder roots grow in the top 50 centimetres of soil and extend beyond the tree’s canopy in search of oxygen, nutrients and water.
Tree roots are more likely to grow over, around or alongside obstacles they encounter in their search for nutrients. If you’re concerned about your home’s foundation, it’s important to note that typically the soil directly around your home is dry and sterile. These are not conditions that attract feeder roots. But even if they do, these fine roots aren’t strong enough to grow through a well-maintained, solid concrete foundation.
On the other hand, tree roots are sensitive to what happens above ground. Frequent foot or vehicle traffic (such as in a driveway) that compacts the soil or covering exposed tree roots by adding a patio, sod or soil can affect nutrient availability and potentially damage the roots and harm the tree.
When choosing where to plant a tree, consider whether the roots will be affected by high traffic. Avoid decreasing or increasing the grade by removing soil or adding fill. Also consider how wide the tree’s branches will spread as it matures. You’ll want to give the tree enough space to grow into its full height. The suggested minimum distance is three metres away from your home or any outbuildings.