I built some out of landscape timbers for my wife's flower beds. Stacked 3 timbers, staggered the ends like you would with bricks, augered a hole down through all 3 timbers in 2 spots on each corner (8 spots total), just each side of each corner and staked to the ground with rebar. That made it about 12 inches high if I remember. You could really easily do 6 rows like that, and it would hold together nicely. Used landscape timbers are usually available cheap, if you look hard enough. Mine are narrow since they're just for flowers, but my brother has built a LOT of raised beds in his garden, and he says that the ideal width is between 24 and 36 inches. 24 inchers for single rows of stuff like tomatoes and peppers, 36 inches for two staggered rows. You'd think you'd want to make them big to make more space, but in most cases you just end up with more dirt to mulch/weed because you don't use it all.
One thing to keep in mind, soil temperatures can get pretty high in raised beds, and they need considerably more watering than planting in flat ground.
Also, must say, I don't plant garden plants in raised beds. If I don't plant straight in the ground, I use containers like buckets or whatever suits what I'm trying to grow.
Last edited by Otis; 01/07/13 01:59 AM.