Thoughts on planting mondo grass under a Silver Maple(30yrs old), some roots visible above ground. Maybe add 3" of soil only where planting the mondo grass, in between the surface roots. cover lightly with pine straw. planting starting at least 4' from trunk. Water will be by hand.

This is to make them look better and prevent the cutting off top of surface roots by lawnmower. I read not to cover the surface roots with soil and to not suffocate the other areas. will the tree compete with the mondo too much for it to thrive? Actual personal experience is preferred. Thoughts or recommendations where to find more info great too.

Please help!