Here at Nature Hills, we get asked a lot of questions about planting trees. People want to know if tree roots will grow into and damage pipes, water and sewer lines.
Sure, it’s true that some plants have aggressive roots and some trees are very surface-rooted. Certain soil conditions may cause a tree to adapt their typical style.
And of course, everyone's pipes are different. An old, cracked Orangeburg or clay pipe certainly tells a different story than new PVC pipe and steel pipes.
All roots are there to find food, oxygen, and water, and to anchor the plant in the soil Typically, most tree roots can grow in any direction in a quest to find food and water.
That's right, roots don't grow in perfect concentric circles. They also don't grow in a uniform pattern out away from the trunk.
Especially as the tree ages, active feeding roots can grow well beyond the spread of the branches. This is called the dripline.
To learn more, researchers have very carefully excavated the roots of many kinds of trees. Their goal was to learn exactly what is going on under the ground.
We now know that trees may send down a handful of deep roots. These deep roots grow to the water table as a precaution against drought. They also act as an anchor to keep the plant upright.
However, the researchers found that the majority of the roots are located in the top 18-24 inches of soil! They also found that the roots may grow 2 or 3 times as far away as the dripline.
When a water pipe becomes damaged from age or an impact, it slowly leaks water. You can bet that tree roots will quickly jump on that water source.
Aging or damaged pipes are a perfect source of water and oxygen for any plant. Roots will quickly grow inside of weak pipes and can plug them up with a thick mass of roots.
Did the tree cause that pipe to fail? Possibly, if it was an older pipe and a tree root expanded enough to push that pipe a bit out of the way.
But there are many other reasons a pipe can fail. It may not always be the fault of the tree.
Bottom line, a damaged, seeping pipe does create an opportunity for roots to enter. You might notice slow drains, gurgling sounds and unpleasant odors as indicators that you have a plumbing issue.
Seek help from a trusted plumbing professional if you suspect tree roots in your pipes.
If you have mature trees on your property, it's also wise to think ahead. Flush a regular course of root preventative that you find at the hardware store. Follow directions on the label.
Root intrusion where trees are the main cause of mechanical damage to a foundation is rare. They will, however, opportunistically seek water if there is a drainage problem near your foundation.
If you have a huge tree planted near your foundation, please know that freezing and thawing or periods of rain and drought can cause some expansion and shrinkage of the roots. Mitigate your risk with professional advice from an arborist in your area.
Please, don't plant huge trees right up against your home. Remember, roots of both trees and shrubs grow toward food and water.
Pull up tree "volunteers" as soon as you notice them around your home. Plan your landscape carefully to maximize your enjoyment of beautiful trees.
Now you know that tree roots grow to find water and nutrients. As you might imagine, septic drainage fields are a prime resource for both.
Trees on your property will likely grow many roots in the direction of your well or septic tank. You can try chemical treatments, geotextile or metal root barriers, replacing trees every 10 years or so, and limiting selections to slow-growing trees with smaller root balls.
But honestly, none of those are ideal solutions for your critical septic plumbing system.
Rather than trying to prevent root growth, we have a different idea. In the long run, it's a better choice to make different plant selections in this situation.
So what is a better type of plant to grow on septic mounds? Try shallow-rooted plants, like Perennials and Ornamental Grasses. These are excellent plants that are much less of a worry.
Extremely hard or compacted soils make it difficult for roots to grow down into the soil. In those circumstances, the planting site can cause roots to stay closer to the surface.
If you plant a tree that prefers well-drained soil in a site that is too wet, it will grow roots closer to the surface in a search for oxygen. So even though this tree may not normally display shallow roots, it will adapt to overcome environmental challenges.
We recommend looking at the Plant Highlights for soil and moisture requirements. They are found on every product page of our website.
Improve drainage and soil condition by bringing in more soil in a mound. Amend with compost, and top-dress with a thick layer of wood chip mulch. The mulch will break down over time to improve soil condition.
In these circumstances, you'll want to be sure to use a full bag of Nature Hills Root Booster to support the needs of your new tree. Follow planting directions on the label.
Do you know where your water lines run on your property? Call 811 to request utilities flag their buried lines and underground pipes several days before you plan to dig. Start here: https://call811.com/Start-Here/Homeowners
Some trees are well-known for having "aggressive" root systems. These varieties include Silver Maples and Willow trees.
Remember that old commercial? It's not nice to fool Mother Nature.
Why not give these gorgeous, large trees room to spread their root systems out? Plant them well away from any structure where they can grow. Allow them the space they need to do their thing without concern.
It's not a good idea to use these large trees close to your home. As they mature, there can be too much risk of further damage to at-risk cement, pipes, walls and septic drainage fields.
All of these trees make great additions to shelterbelts and windbreaks. Weeping Willows look fantastic along the edge of a property or pond as a "destination" focal point.
Don't worry! There really is a place for every plant.
A fun idea is to use semi-dwarf fruiting trees as part of a modern edible landscape. Or use tree-form shrubs like Lilacs and Hydrangeas that have been grafted to a standard. Filter by size on our site to see our full list of trees that stay small.
For other suggestions suited to your area, try your local Ag Extension office. It's free, and staffed with helpful master gardeners who know the trees that work best in your geographic conditions.