I built cedar raised beds out of cedar decking, 3 pieces 5/4" x 6" x 8', actual dimensions were 1" x 5.5" x 8', plus 1 - 2 x 4 cedar. I made 48" x 96" boxes. I cut 1 of the cedar deck pieces into 2 - 48" long pieces. For the corners, I cut the 2 x 4 into 8 - 5.5" long pieces. I then screwed 2 of the 2 x 4 pieces together to form a 4 x 4 block. I used these as the inside corner to screw the decking to. The total cost was $60 to build 2 cedar beds. The other option would have been to make them double height, by cutting the 2 x 4's 11 inches long. This is more expensive then the boxes Ana did, but I could not find cedar fence slats, they appeared to be Northern White Pine which would have deteriorated quickly. I obtained the lumber from Lowes.