I've had good results with putting down landscape fabric over the entire garden, then cutting holes through it to put in the plants. Really helped deal with the weed problem that came up after the rototilling, that I just couldn't keep up with. Then once everything was harvested, I pulled up the fabric, ran it all over with the dethatcher rake on the back of the lawn tractor, and seeded it with miniclover. That established before frost and kept the weeds from coming back the next spring. That year I only used fabric for the rows of tomatoes and peppers and left the clover growing between the rows. It makes excellent ground cover and after a couple of cuttings doesn't get any higher than 4 - 6".