Cover the surfaced tree root

Asked August 3, 2013, 5:36 PM EDT

I have 2 matured trees (20 plus years) in a sloped front yard. One is Live Oak, one is Maple. Both trees' many roots surfaced to the ground over the years. Because of that , and also due to the thick leaves, the grass have not grown well and thin-out in a 9-ft radius circle centered around each tree. I would like to improve my lawn.

1). Can I cover the surfaced roots with sods or dirt ?

Someone told me that if I cover the already surfaced roots with sods or dirt, the trees will die? Is it true?

2). What kind of grass/sod is best for heavy shady area?

Many Thanks

Collin County Texas trees and shrubs horticulture

3 Responses

Your problem is a combination of slope and shade. As the grass thins because of the shade, soil erodes exposing the tree roots. If there is no grass or groundcover to hold the soil, the soil will erode away. Turf grass may not be the best solution where shade is a contributing factor. You may want to try planting a groundcover. You can use erosion fabric to hold the soil while the groundcover roots in. Go to which has a great plant selection list for plants in this area. Plan to plant the groundcover this fall or next spring. Bring in compost not heavy soil. Placing a swallow amount of soil on tree roots will not harm the tree. St Augustine is the most shade tolerate grass that’s grows in the shade.

Dear Dotty:

Thanks for your reply. I will consider the ground cover option.

I have follow-up question:
My 2 trees have circular walled-beds about 3 feet radius centered around each tree trunk. The exposed roots are usually outside the bed areas. If I thin-out the trees to allow more sun lights in, can I grow St. Augustine outside the circular beds? Can I put sods on top of exposed roots without killing/hurting the trees?

Thxs, James

Believe it or not, pruning stimulates growth. That is why we always say, do not top trees. Now if the area would receive light under the trees by raising the canopy, that is worth trying. This means removing lower branches to allow the morning and afternoon sun to reach the ground where you want to try St Augustine. Thinning out branches up in the canopy of the tree will stimulate more branching and in a few years you will have even more shade. Consult an arborist if you are not sure. You can place sod on top of the tree roots without hurting the roots.