How to Build a Weather-Resistant Planter

Whether big or small, used in pairs or on their own, planter boxes are a cheery way to flank an entry, break up an expansive patio, or simply add a splash of color to a small yard. This roomy rectangular version gives you plenty of space for your favorite bloomers, and, knowing that large planters are tough to store during the off-season, This Old House senior technical editor Mark Powers opted to build it from cellular PVC. “The material is easy to cut, it holds up well in heat and cold, and it won’t rot when exposed to soil and water,’ he says. Beadboard detailing and a bright coat of paint add extra charm during those inevitable April showers, too. Read on to learn how he turned trim and beadboard pieces into an eye-catching landscape accent.

Material: AZEK cellular PVC trim and beadboard

Paint: Custom color by C2 Paint

Overview of a Weather-Resistant Planter

Project Timeline:

• Friday: Make cuts for the sides and bottom, create a jig, and glue the side frames together.
• Saturday: Assemble the sides of the planter, install the bottom boards, and cut and install the cap.
• Sunday: Fill the fastener holes, and sand and paint the planter.

Step 1: Cut PVC for the Sides and Bottom

Determine your planter’s dimensions or use those in the drawing on the previous slide. Set up a plywood work surface. Using a miter saw, cut a 1×4 leg to length and screw a stop block to the work surface against the cut end of the piece. Repeat to make four legs from 1x4s, then cut four legs from 1x3s. Reposition the stop block as needed to cut four long 1×3 rails, four short 1×3 rails, 24 beadboard pieces for the sides, and thirteen 1×4 boards for the bottom.

Step 2: Form Side Frames and Make a Jig

Position rails and legs for a long side and a short side on the work surface. Screw blocks around the pieces to hold them in place and keep the frames square when gluing them in Step 3.

Step 3: Glue Side Frames

Lift one end of a rail, and apply glue to its end and the edge of the adjacent leg. Lower rail into place. Repeat for all joints. Let glue dry at least 2 hours before removing frames from the jigs. Make the second set of frames the same way.

Tip: Once glue is added to the end of a rail, lift the rail at the center so that it bends slightly. This makes it easier to butt the rail up to the leg without scraping glue off the surfaces.

Step 4: Mark the Placement of the Beadboard

The planter’s short sides will be attached between the long sides, so you’ll need to leave space at the ends of the long sides for them. Measure the gap by using the edge of a piece of beadboard and a 1×4 set on edge as a spacer; mark the gap at the ends of both frames for the long sides. Dry-fit beadboard pieces across the long sides, adjusting them so that they cover the open space between the legs but fall short of the gaps you marked. Center the slats on the frame, and mark the spot where the first beadboard piece will sit.

Step 5: Install the First Piece of Beadboard

Apply glue to the top and bottom of the face of a piece of beadboard and to the frame where it will sit. Set the piece in place and secure it to the frame using four 1-inch screws at the corners.

Step 6: Install the Rest of the Beadboard

Glue the remaining beadboard pieces to the frame, facedown, fitting the tongues and grooves together tightly. Glue and screw the middle and last pieces to the frame in the same manner as the first. Install the beadboard pieces the same way on the remaining long side and on the short sides.

Tip: Make sure the beadboard is square and flush with the frame as you install it. You can hold a scrap block against the first piece you install to check for square, then keep checking the run as you add more pieces.

Step 7: Assemble the sides: Make and Attach the Ledges

To create ledges for the planter’s bottom boards to sit on, rip an inch off a 1×4 and cut two 1x1s to the length of the beadboard run on the long sides. Using 1⅝-inch screws, attach each ledge to the back side of the beadboard pieces, flush with their bottom edges. Secure a screw at each end of the strip and through every other piece of beadboard in between.

Step 8: Join the Sides Together

Apply glue to the edge of a short side and the gap on the interior of a long side. Turn both sides on their top edge, and join the glue-bearing surfaces together so that the face of the short side forms a corner with the edge of the long side. Clamp the corner as shown to hold the sides together. Using a drill/driver with a ⅛-inch bit, drill a pilot hole through the face of the long side into the edge of the short side, at the top, middle, and bottom. Drive a 1⅝-inch screw into each pilot hole. Repeat for each corner of the planter. Let glue dry for at least 2 hours.

Step 9: Add the Bottom Boards

Once all four sides are joined, turn the planter right-side up. Apply glue to the top of both interior ledges, then drop the bottom boards into place. When all the boards have been added, check that the planter’s width at the center is the same as at the ends. Use 1⅝-inch screws to fasten the boards to the ledges.

Step 10: Cut and Glue Down the PVC Cap

To make a cap with a 1-inch overhang all around, add 2 inches to the length of the long sides and cut two 1x3s to this length. Apply glue to the face of a 1×3 and the top edge of a long side. Set the 1×3 in place, checking the overhang’s spacing by holding a 1-inch block against the sides of the planter. Repeat with the second 1×3. Measure the distance between the long cap pieces and cut two short cap pieces to size. Glue them down in the same manner as the long pieces.

Step 11: Finish Installing the Cap

Drill pilot holes at the middle and ends of each cap piece. Drive 1⅝-inch screws into the holes.

Step 12: Fill Fastener Holes

Fill fastener holes with spackling paste until the paste sits just above the surrounding surface. Let dry before sanding flush with the surface, using fine-grit sandpaper.

Step 13: Sand and Paint

Sand and paint the planter. Lightly sand the planter’s exterior surfaces, and wipe them down with a tack cloth to remove dust. Apply two coats of latex exterior paint. Let paint dry for at least seven days before filling the planter.

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