A quick way to make your raised bed gardens is to use cinder blocks to enclose the garden area. Cinder blocks are about $1.30 each. I like my gardens to be small enough to reach across, so I used 24 blocks for a cost of about $30.
Line the bottom of the area and under the cinder blocks with thick layers of newspaper to kill weeds.
Fill garden area with compost, leaves, sand and soil. Cover with a landscape cloth that allows rain to run through. Allow the heap to rest for a week. Then pour a beer over the whole pile. Cover.
Fill the holes in the concrete blocks with garden soil and plant with herbs and flowers. Petunias and marigolds help repel pests and beautify the cinder blocks.