We have two raised garden beds in a rocky area. Inside the beds is fine but around the beds on the ground is the problem. Since we're not using chemicals we've developed an insurmountable stand of weeds (lambs ear, dandelion, and some mixture of tall and short grasses etc). The area is semi rocky as the old homeowners put cheap rocks down. It is now impossible to weed. We don't want to use any kind of chemical or plastic barrier. We also want to save money. Is it possible to put down some thick cardboard over the whole area and then cover that with topsoil and then seed it over with grass seed to make a lawn? We want to do a lawn rather than rock so our one1/2-year-old can play on it. Once the cardboard breaks down it would seem that the grass would have had a chance to grow in well and would mostly out compete any weeds that would try to come up. There would still be weeds but it would perhaps be more manageable and kind of reset things. Thoughts?