Covering vast surface roots of large ash tree - Ask Extension
Have a large ash tree with area that won’t grow grass due to shade. Also, there are extensive tree roots on the surface. I’ve received different s...
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Covering vast surface roots of large ash tree #928926
Asked April 20, 2026, 10:18 AM EDT
Have a large ash tree with area that won’t grow grass due to shade. Also, there are extensive tree roots on the surface. I’ve received different suggestions from landscapers. I don’t want to suffocate the tree with lots of dirt etc. I hope to kill the minimal grass in the area and there are so many roots I think tools will damage the roots. I didn’t know if using cardboard with ?? Compost over top or something else? Also, this area will have tons of leaves fall on it in the fall. I greatly appreciate your help!
Larimer County Colorado
Expert Response
Hi Cathy,
What if you just put a thick layer of mulch (4-5 inches deep) around the tree and where the roots are located? You can extend out as far as you want from the trunk. This would be a better option than mulch or cardboard, since mulch is porous. As the grass starts to grow through, you can dig it out or use herbicides. With a thick enough layer, there won't be a lot of grass growth.
What if you just put a thick layer of mulch (4-5 inches deep) around the tree and where the roots are located? You can extend out as far as you want from the trunk. This would be a better option than mulch or cardboard, since mulch is porous. As the grass starts to grow through, you can dig it out or use herbicides. With a thick enough layer, there won't be a lot of grass growth.
