Dynamic Raised Garden Bed

Lay a 4x4 post on the ground and lay the 6 ft 9 in side panel boards on top of it. Align the panel-board edges flush with the post, then attach with six screws per board — three per side of the joint. Repeat for the second post on that wall.

Align the second wall's panel boards along their posts the same way. Then lay that assembly on the ground with the panel boards standing up in the air, lay a 2x4 across the top of the boards (a helper holding the boards steady makes this much easier), and screw the 2x4 to the panels with it pointing opposite the posts. This temporary brace provides the joint support you'll need in a few steps — get it solidly attached before letting go of the assembly.

Align the front panel edge with a side wall panel, with a helper holding the panels in place. Attach each front board to the side panel with six screws: three along the panel-to-panel edge, and a parallel set of three through the front board into the 4x4 post for extra security. Repeat for the other side.

Draw a centerline down the 3 ft joint-support board. Lay the six back-panel boards flat on the ground, line them up, then place the joint support on top along your centerline. Drill through the support and into each panel board in a zigzag pattern, three screws per board.

Align the back panel's edge with a side wall panel and attach the top board first, using the same two-row screw pattern (into both the side panel and the post) as the front wall. Work down from the top board to the bottom, then repeat on the other side. The garden bed box is now complete.

Mark each backdrop post 2 ft from one end. Decide whether you want 2 ft or 3 ft of backdrop exposed above the bed and be consistent across every post — mixing heights will make the top rail visibly out of level. Align a post's marked line with the top of the back panel, hold it plumb, and attach with at least three screws; check it's level with the first post you set before moving to the next. Space the remaining posts evenly, then lay the two top rail pieces across all five posts, butted together over the center post, and attach each with two screws per post.