Build a beautiful 4'x4' raised garden bed from naturally rot-resistant cedar. This intermediate-level project takes about 2-3 hours and creates a sturdy planter perfect for vegetables, herbs, or flowers. Great for beginners ready to try their first outdoor woodworking project!
Choose a level spot in your yard that gets appropriate sunlight for what you'll grow. Lay out all your materials and tools in your work area. Check that all cedar boards are straight and free of major defects.
Using your circular saw or miter saw, cut four pieces of 2x10 cedar to 48 inches long (these will be your side panels). Cut four pieces of 4x4 cedar posts to 16 inches long (these will be your corner posts). Wear safety glasses and a dust mask while cutting.
Use 120-grit sandpaper to smooth any rough edges from your cuts, especially where you'll be handling the boards during assembly. This prevents splinters and gives a cleaner finished look.
On each 4x4 corner post, measure and mark two drilling points on adjacent faces, 3 inches from the top and 3 inches from the bottom. These marks should be centered on each face (about 1.75 inches from each edge). You'll have 4 marks per post, 16 total.
Using a drill with a 1/8-inch drill bit, drill pilot holes at each mark you made. Drill straight through the post, being careful to keep the drill perpendicular. These holes prevent the wood from splitting when you drive in the screws.
Stand two corner posts upright on your work surface. Position one 48-inch side board between them so the ends are flush with the outer edges of the posts. The top of the board should be flush with the tops of the posts. Drive one 3-inch exterior screw through each pre-drilled hole into the end of the board.
Take another 48-inch side board and attach it to the opposite sides of the same two corner posts using the same method. You now have a U-shape with two parallel sides connected by corner posts.
Stand your U-shape upright. Attach the remaining two 48-inch boards to the open ends, connecting them to the two remaining corner posts. Work on a flat surface and check that corners are square as you go. Drive screws through all pre-drilled holes.
Use a carpenter's square to verify all four corners are at 90-degree angles. Measure diagonally from corner to corner in both directions—the measurements should be equal if the box is square. Adjust if needed before proceeding.
If you want a bottom to help contain soil (while still allowing drainage), cut 1x4 cedar boards to 45 inches and lay them across the bottom of the frame, spaced about 1 inch apart. Attach with 2-inch screws into the bottom edges of the side boards. Leave gaps for drainage.
With help if needed, carefully move your completed planter box to its permanent location. Make sure the spot is level—use shims or adjust soil beneath if necessary. The 4x4 posts will sink slightly into the ground for stability.
If desired, staple landscape fabric to the inside walls of the planter to help prevent soil from washing through gaps while still allowing drainage. Cut the fabric to size and attach with a staple gun, leaving the bottom open.
Fill your planter box with a high-quality garden soil mix, leaving about 2 inches of space from the top. Water the soil thoroughly before planting. Now you're ready to add your vegetables, herbs, or flowers!