If you don't have tall grass available, you have to chose between plastic and hay or straw. I don't recommend plastic. It is ugly and weeds grow under it. The weeds rise and make the plastic look like Jiffy Pop after it pops. If you decide to use plastic, place the plastic over each row and staple it down securely. It is not pretty, but you can cover it with grass clippings or hay for aesthetics. If you don't use a weed suppressant of one kind or another, you will be constantly at war with the weeds, a war you never win. Hay is tricky, and some weeds will grow especially if you don't use enough. But it is more pleasant to look at and is healthier for your garden because you can till it in at the end of the season. But be very careful that you use hay without seeds. If your hay has seeds, you will be in living hell!! Salt pond hay from Canada is supposed to have no seeds. Be careful!