Q.Can I put landscaping plastic on top of cardboard instead of mulch to kill grass? I want to put down rock.
I am trying to maintain the rock garden that was there when we bought the house. I cannot keep the grass out. Had it completely removed and it just grew back. I want to put the rock back in and plant perennials. Do not want to cover entire area with mulch.
Certified GKH Gardening Expert
Clear plastic, alone, when left on for several weeks during the heat of summer will kill grass. You also can use an herbicide containing glyphosate to eliminate grass. (Always read and follow label directions.) Then you can apply landscape fabric topped with rock to help keep out weeds.