Dean, I'm currently building a raised bed in my front yard. I will fill it with 1/4 native clay soils, 1/4 coarse sand, 1/4 quarter-inch pumice, and 1/4 ground coir or sphagnum moss. These last 3 items I buy in bulk (cubic yard) from material suppliers. Here's a picture of the construction and a drawing made earlier this year when we (bananas.org) were discussing heated raised beds. In the current construction the french drain is already in place and drains to the street.
