how thick does mulch have to be to stop weeds?
i made a border around my flower garden where i used a weed wacker to dig up grass, then i put down some mulch.
2 weeks later, i now see grass poking thru the mulch. if i buy more mulch to put on top of the existing mulch, will that choke out the grass?
or do i have to pick up the mulch and put down a weed barrier and then put the mulch back? i usually cut up black plastic trash bags for my weed barrier.