Actually, coastal bermuda doesnt like being smothered. Sedges are a problem too. I wouldnt plant in ground. Plow it, smooth it, smother it. Thick black plastic, thick cardboard, wider than the whole garden. Then build raised beds- fresh dirt. The old dirt has many decades of seeds setting in it waiting for same things your veggies are. Water, fertilizers, sun. You would never know if you killed the original plants or not. Raised beds are above where winds and seed throw can get. Drifting soil and seeds are easier to keep cleared away. No poisons in the soil for plants to uptake. Increased yields in raised beds.