How To Keep Grass From Growing Around Crepe Myrtle

Question From: MICHIGAN
Q: as a result of losing a 4 1/2 story historic basswood tree 2 yrs all the myrtle surrounding the tree, one whole side of house last summer starting spouting grass.. Not what appears to be common lawn grass, but a very tall broad green type of grass.. Spend hours pulling last summer, but I can see it is coming back with a vengeance. I prefer the myrtle, which is a whole side of my house, as I could never grow anything there. Any thoughts what I can do, that would kill the myrtle also. Thanks for any suggestions.

A: I would cover the are with cardboard and then cover it with 4 inches of good organic mulch. The cardboard will smother the plants. Do overlap it so the plants do not grow through the cardboard. Best And Happy Yardening, Nancy