Click below to listen to my 2 min. Garden Bite radio show: Surface root conundrum
Surface roots of trees can be a real pain in the patoot when trying to mow! I know… but there are some real DON’TS when it comes to making your mowing life easier. While I’m lucky with the yard I have now, I still have a Hackberry that’s not easy to mow around.
But I found a way around it!
In a previous residence, I had Silver Maples, they are notorious for large surface roots as they require more oxygen. The smart thing to do is to consider the issue BEFORE it’s a problem….
- Keep all trees at least 10 feet from home foundations, driveways, and utilities. Double that distance or more for particularly invasive species, especially larger varieties.
- Plant all trees away from in-ground pools and their water lines. Trees seek water and will not hesitate to invade lines or snake under even the most perfectly installed pools.
- Plant trees with shallow roots some distance away from gardens and with shade areas in mind.
Some folks try to build a raised bed over those roots, adding a bunch of soil on top. That’s not a good idea, nor is cutting them out! This is from my friend, Faith Appelquist of TreeQuality:
It is tempting to cut these roots off to make mowing easier, but remember that the roots are growing there for a reason, and cutting them out will simply make the tree’s plight worse. After all, destroying a large number of surface roots can easily permanently damage the tree, if not kill it altogether. And roots always grow back.
She added: I’ve had a lot of success with changing the level around surface roots with topsoil and turf, basically burying them just below a new surface.
That doesn’t mean a garden on top of those roots….
When you cover them with soil, you’re taking away needed oxygen to the plant and those roots that don’t die will work their way back up to the surface again. Those tree roots may also compete with your new plants for nutrients. If you’re having a problem mowing around those massive surface roots, don’t get out the axe, get some mulch.
A 2 to 3 inch layer of wood chips, leaves or cocoa bean shells is perfect to keep the grass or weeds tolerable while maintaining the health of your tree. You can place landscape fabric down but I don’t recommend plastic. You could plant perennial groundcovers in between the roots.
Notice how the mulch is properly placed. It is NOT piled like a volcano! You could also use pea gravel or even place permeable pavers within the surface root spaces, if you can find the right fit.
Under plantings around some trees is possible, such as the case of my Hackberry. Lamium and ginger are 2 groundcovers for shaded areas, while ajuga will handle some sun. The roots of the groundcovers won’t be enough to interfere with your trees roots.
Faith also recommends planting deep rooted trees such as Kentucky coffeetree, buckeye, ginkgo, oaks and elms. My hackberry is also a good tree, those surface roots aren’t really that bad!!
Additionally from Faith: Some tree species seem to be more prone to surface rooting than others: maple, ash, willow, honeylocust and cottonwood are big offenders in my experience.
More information on surface roots.