Some deck planters are wood containers that actually hold soil. Others serve as decorative containers into which you can place potted plants. The type shown here combines the features of both: an attractive planter box that holds a large plastic tub with holes in the bottom for drainage.
Tubs are available at garden or home centers. Another option is to order a galvanized liner from a sheet metal shop; the liner can be custom-made to fit any size planter.
Whichever type of planter you choose to make, be sure water can drain freely out the bottom and plan where that water will go. Drained water trapped in a cavity below the planter could cause decking to rot. Most decorative plants need less than 1 foot of soil depth. Rather than loading a tall planter with unnecessary soil, build a shelf inside.
A bench is even easier to build than a planter. A platform that is 16 inches wide and 17 inches high will be comfortable for most people.
Expect to spend several hours building two planters and a bench. You'll need to be able to measure and cut boards, plus fasten them with nails or screws. Before you begin, purchase a liner and design a planter to fit around it.
What You Need
- Tape measure
- Circular saw
- Layout square
- Framing square
- Squeeze or pipe clamps
- Lumber for the planter and the bench
- Screws or nails
- L-shape strap ties with screws
- 6-inch carriage bolts
This simple planter is made primarily of pressure-treated 5/4x6 decking, but you can vary the height and width to suit your deck. The cleat can be set to suit the height of the plant container you'll use. Trim pieces can be butt-jointed or mitered.
To make the bench frame, cut two 2x4s to fit between the planters and attach joists between them. Use 4x4 posts to support a frame longer than 8 feet.
Step 1: Cut and Build Planter Sides
Cut pieces of 5/4 decking for the sides of the planter. To build each side, clamp the pieces and attach a 2x6 brace, which also acts as a cleat to hold the bottom pieces. Cut the brace 2 inches shorter than the width of the side and attach it with screws.
Step 2: Attach Sides and Trim
Hold three of the sides together with clamps and drive nails or screws to fasten them together. Attach the fourth side in the same way. Cut pieces of decking for the shelf. Check the structure for square, then attach the shelf pieces to the cleat. Add the top and bottom trim pieces.
Step 3: Make the Cap
To make the cap, cut decking boards with 45-degree miters and assemble them with L-shape strap ties. The frame should overhang the top trim by 1-1/2 inches on all sides. Set the liner in the box and then fasten the cap using 2-inch deck screws sunk into the top trim piece.
Step 4: Construct a Frame
For each bench, measure between two planters and construct a 2x4 frame with crosspieces every 2 feet or so. Set the finished frame between the planters and fasten it into the planters with four 3-inch fasteners.
Step 5: Cut and Space Seat Slats
If a seat is longer than 8 feet, add 4x4 supports every 6 feet or so. Cut seat slats from decking lumber and fasten them to the frame with screws or nails driven into the seat joists. Space the seat slats as you would for decking and allow them to overhang the frame by 1 or 2 inches.
Step 6: Attach to Deck
To attach the posts and the planters to the deck, drive toenails or angled screws. Drill a pilot hole 2 inches above the deck at about a 60-degree angle. Install a 3-inch deck screw or 16d nail.