By the way, what are you using to make walls for your raised beds? Most people use wood, but I like concrete paving stones stood on end. I have options for 8" walls, 12", or 16". My soil is so clayey that I can leave a "curb" of clay at the bottom of a bed and stand an 8" paver on top of the curb, but still have a wall 12 inches tall or taller.
The pavers can cost less than $1 per linear foot.
8" x 16" x 3/4"
12" x 12" x 1"