We made a 30x20 foot garden in our back yard with plastic and cement blocks. You do not have to remove grass. Put down plastic or a thick layer of news papers, and place cement blocks on top around the edge of the space. Then, fill it with compost or manure. You have a garden without weeds or grass for years. Add more compost as needed every year. I get manure from Lowe's in 40 pound bags, I have a garden all the year, I also make flower beds the same way.