Using rocks under trees over grass
I had big plans for landscaping under my backyard apricot tree (big & old)using rocks and bark with edging to separate design.
The lawn surrounding the big bare area under the tree is Bermuda grass and there are sections and clumps of Bermuda grass and weeds in the area I'd like to cover with decorative rocks.
I'd planned to just put black plastic down and pour the rocks and wood chips over it to smother the grass, leaving a small circle around tree trunk open to water.
BUT . . . I've now read you can't put plastic down under trees as it will smother the tree roots, which spread just below the soil surface for many feet out (plastic keeps air and moisture out).
So ... if I leave off the plastic and do only rocks/bark, won't the grass and weeds continue to grow through? I don't want to use grass killer as it might harm the tree root, too, and using a rototiller to dig up the grass will also tear up the tree roots.
Help! Unfortunately, I've already bought all the stuff (rocks, chips, black plastic)and would love to get this huge bare area looking better. How can I do it without hurting the tree but getting rid of the grass/weeds?