How to Build a Durable Cedar Raised Planter Box

CEDAR is the gold standard for outdoor garden beds because it naturally resists rot, insects, and warping without needing toxic chemical treatments. A well-built planter elevates your gardening, saves your back from unnecessary bending, and provides excellent drainage for your herbs or vegetables. Achieving a professional finish means squaring your frame and pre-drilling every screw hole to prevent the wood from splitting. When done right, this box will serve as a permanent fixture on your patio or deck for at least a decade, aging gracefully into a handsome silver-gray color.

1. Cut Cedar to Size. Measure and cut your 2x6 cedar boards to size using a circular saw or miter saw. You need four long pieces for the sides and four shorter pieces for the ends, plus four 4x4 posts cut to height to serve as corner anchors.
2. Prevent Wood Splitting. Measure the screw placement on the ends of your boards and use a drill bit slightly smaller than the shank of your screws. This prevents the cedar from cracking when you drive the fasteners in.
3. Square the Corners. Place the 4x4 posts upright on your workspace and align the side boards against them. Apply a bead of exterior wood glue to the contact surfaces before driving the stainless steel screws through the boards and into the posts.
4. Build the Walls. Stack the subsequent rows of 2x6 boards onto the corner posts, ensuring they are flush with the bottom boards. Continue screwing the boards into the posts until you have reached your desired height.
5. Add Support Cleats. Screw small 2x2 cedar cleats along the inside bottom edge of the long walls. These cleats will support the floor boards or the wire mesh screen.
6. Sand and Seal Drainage. Lay heavy-duty hardware cloth or spaced cedar slats across the cleats for drainage. Sand any rough edges with 80-grit sandpaper to prevent splinters.