I like to use 6-8 layers of newspaper to cover the potting mix/soil. I give that a good soaking and then pile on a few inches of shredded leaves that I keep piled up near my garden. It holds in the water quite well and helps in my war on weeds. I've had to pull a couple of weeds every week or so since I started using this plan of attack. Before that I was watering and pulling weeds daily....and sometimes it was like an endless battle against the weeds. At times they seemed to grow back at one end of the garden before I could get to the other end.....and the other end was only ten feet away.