I have had excellent results on a 10,000 sq.ft. lot in California with an in situ compost process like you describe. Just put down 6 inches of chipped trees fro

I have had excellent results on a 10,000 sq.ft. lot in California with an in situ compost process like you describe. Just put down 6 inches of chipped trees from a tree trimmer, or the city compost yard, and let it decompose. Keep layering it on, year after year (less needed after the first time). You have to go thicker than you probably will imagine. The initial load of chips filled my driveway to a height over my head. And be careful to keep the compost away from the trunks of existing trees, or it will tend to rot the trunk, which will kill the tree. It costs practically nothing. You should be able to get the chips for free.