When we built and moved into our new home I had the contractor save all the cardboard boxes that the appliances came in and we saved all the boxes we used for moving. When we did the landscaping I laid them down on top of the weeds and layered mulch and compost on top. There is actually a book out called "Lasagne Gardening" which is where I got the idea. You don't even need to take out the weeds just layer on top of them. The cardboard smothers the weeds and then decompose over several years. The contractor thought we were nuts but in an area that has heavy clay soil where things struggle to survive we have beautiful loose mulch full of happy worms to work with. You can probably find a copy at the library. It works beautifully for us and you can't see the cardboard when covered with the mulch. Ann in Tn