Introduction: Wooden Planters

About: The official instructable for Popular Mechanics magazine, reporting on the DIY world since 1902.

Sure, you can go to Home Depot and buy $4 plastic planters in a variety of earth-tones. But these will not impress your neighbors nor complement your colorful pansies. This project makes a planter that is handsome enough to be a stand-alone piece of outdoor furniture.

We built our planters from nominal 5/4 (11/8 in. thick) and 1-in. (3/4 in. thick) pine, and 3/4-in.-thick marine-grade fir plywood. Marine plywood is made with waterproof glue so it can stand up to moisture. To extend the life of the planters, we added metal liners made from aluminum flashing that's commonly available at hardware stores and building supply dealers.

Step 1: Materials and Plans

4 1 1/8 x 1 3/8 x 13 1/2" pine (stile)
4 1 1/8 x 2 1/2 x 13 1/2" pine (stile)
4 1 1/8 x 3 x 8 1/2" pine (rail)
4 1 1/8 x 3 x 32 1/2" pine (rail)
4 1 1/8 x 2 x 9" pine (mullion)
2 3/4 x 8 x 81/2" plywood (panel)
6 3/4 x 81/2 x 10" plywood (panel)
4 3/4 x 21/4 x 21/4" pine (foot)
2 3/4 x 2 x 81/4" pine (cleat)
2 3/4 x 2 x 333/4" pine (cleat)
1 3/4 x 93/4 x 333/4" plywood (floor)
1 13 5/8 x 37 5/8" aluminum (tray)
1 10 5/8 x 88 11/16" aluminum (liner)
4 1 1/8 x 1 3/8 x 20 1/2" pine (stile)
4 1 1/8 x 2 1/2 x 20 1/2" pine (stile)
8 1 1/8 x 3 x 14 1/2" pine (rail)
4 1 1/8 x 2 x 16" pine (mullion)
8 3/4 x 6 1/2 x 15 1/2" plywood (panel)
4 3/4 x 2 1/4 x 2 1/4" pine (foot)
2 3/4 x 2 x 14 1/4" pine (cleat)
2 3/4 x 2 x 15 3/4" pine (cleat)
1 3/4 x 153/4 x 153/4" plywood (floor)
1 19 5/8 x 19 5/8" aluminum (tray)
1 17 5/8 x 64 11/16" aluminum (liner)
as reqd. 11/2" No. 8 fh galvanized deck screw
as reqd. No. 20 joining plate
as reqd. 6d galvanized finishing nail
20-grit sandpaper
waterproof glue
exterior alkyd primer
acrylic exterior paint.

Step 2: Cut the Parts and Joinery

Although we made planters in two different sizes, the construction techniques are the same for each so it's easy to modify the designs if you wish. Begin by cutting the frame parts to size. If you're making more than one planter, or planters of different sizes, sort the parts so that similar pieces are grouped together.

Clamp together a group of planter stiles so that their ends are perfectly flush and then lay out the mortises for the rail joints. Repeat the procedure for each group of stiles and rails. As shown in this picture, use a plunge router, edge guide and a 3/8-in. spiral up-cutting bit to make the mortises. To provide a stable base for the router, clamp the workpiece to a similar-size piece.

Step 3: Clamp the Board

Attach a board to your table saw's rip fence, install a dado blade and adjust the fence to cut the tenon cheeks. Then, readjust the blade height, and hold the stock on edge to cut the shoulders at the inside edges of the rails and on both edges of the mullions. Lay out the notch for the tenon haunch at the outer edge of each rail.

Step 4: Cut the Tenons

You can use either a backsaw or dovetail saw to make the cuts. The haunch or shoulder on the tenon is necessary to fill the frame's panel groove at the ends of the stiles. It also adds strength to the joint. We suggest cutting the haunched tenon shoulders with a backsaw. The other shoulders are cut with a dado blade.

Step 5: Create Panel Grooves

With the joints shaped, use a dado blade to cut the panel grooves in the edges of stiles, rails and mullions. Clamp a featherboard to the saw table to keep the stock tight to the fence and to reduce the risk of kickback.

Rip and crosscut plywood to size for the planter panels. Install a straight bit in the router table and use it to cut the 3/8 x 9/16-in. rabbet around the edges of each piece on their inside faces. We like to test the fit of a panel in one of the rail grooves. If it doesn't easily slide into place, adjust the router table setup to improve the fit.

Step 6: Assembly

Since these planters are designed for the outdoors, it's best to use waterproof glue for assembly. Begin assembly by gluing the mullions to the rails. If a planter side has only one mullion, apply glue to the mullion tenons and rail mortises, and use a clamp to pull the joints tight. Compare opposite diagonal measurements to check that the assembly is square. Next, slide the panels into place, spread glue on the rail tenons and stile mortises, and add the stiles. Clamp the assembly until the glue sets. For planter sides with two mullions, it's easier to slide the center panel into position before adding the top rail to the mullion ends.

Step 7: Use a Tall Fence

Lay out joining-plate positions for assembling the four sides of each planter. Clamp a tall fence to your worktable to support when cutting plate slots in front and back panels.

Step 8: Cut Slots

To cut the slots in the ends of the remaining sides, clamp each firmly to the worktable, facedown and cut into the panel edges.

Step 9: Apply Glue to Mating Surfaces

To join the planter sides, spread glue on the mating surfaces and in plate slots. We used a shim to apply glue to the joining plates and slide them into the slots. Next, assemble each planter box and use clamps to pull the joints tight.

It's best to compare opposite diagonal measurements to make sure that each box is square. Let the glue set for about an hour before removing the clamps.
Cut 3/4-in.-thick stock into 21/4-in.-square blocks for the planter feet. Use a sanding block to bevel the edges of each to a 10 degree angle, and nail the feet to the bottom of the planter with 6d galvanized finishing nails. Set the nailheads below the wood surface and fill the holes with a good-quality, exterior wood filler.

Step 10: Cut Side Cleats

Rip and crosscut 3/4-in. stock for the bottom support cleats. Use 1 1/2-in. No. 8 galvanized deck screws to fasten the cleats to the inside of the planter.

Step 11: Cut Drainage Hole

Cut the bottom panels to size. Mark the center of the drainage holes, then bore the holes with a holesaw. Slide the bottom panel into position, and fasten it to the cleats with 1 1/2-in. No. 8 galvanized deck screws.

Step 12: Painting the Planters

Smooth the surfaces with 120-grit sandpaper, taking care to ease all sharp edges. Thoroughly remove the sanding dust and seal all surfaces with a premium-quality, exterior alkyd primer. After overnight drying, lightly sand the primed surface to remove any roughness and, again, remove all sanding dust. Finish the planter by applying at least two coats of acrylic exterior paint, following the manufacturer's application instructions. Make sure that you coat the interior as thoroughly as you do the exterior surfaces.

Step 13: Making the Liners

Use a felt-tipped marker to lay out the liner and tray parts on the aluminum flashing stock, and cut out the pieces with metalcutting shears. Mark the center of the drainage holes on the liner tray pieces and mark the bend lines on all parts.

Use a holesaw or shears to cut the drainage holes. We made the holes in the tray slightly smaller than those in the planter bottom–this prevents water from collecting on the plywood surface. To bend the aluminum, clamp a board on each side of the metal with the board edges aligned with the bend line. Then use the boards to guide the 90 degree bend.

Step 14: Insert Liner

Slide the liner inside the tray and bore 1/8-in.-dia. holes for blind rivets where the liner ends overlap. Use a wood block on the exit side of the drill bit to support the metal when making the holes. Install the rivets to fasten the liner ends together and then attach the liner to the tray in the same way. If you wish, staple a piece of fiberglass screen to the bottom panel, over the drainage holes, before installing the liner to keep soil from falling out of the planter.