How to Build a Cedar Potting Bench

Complete plans for building a potting bench.

Everything you need to get started

In this article, we’ll show you how to build this cedar potting bench in a weekend. We designed this bench to be strong without complex joints. An experienced woodworker can complete this potting bench in a day. If you’re a beginner, allow two or three days.

You’ll need basic carpentry tools like a tape measure, large and small squares, and a chisel. You could make most of the cuts for this potting bench with a circular saw. However, a miter saw will ensure perfectly square end cuts, and a table saw is almost essential for cutting the grate slats. If you don’t have a table saw, ask a friend, neighbor or the staff at the lumberyard to cut the pieces for you. You’ll also need a drill with bits and a jigsaw.

Use the Shopping List in the Additional Information below to buy your materials. We used cedar for our bench, but pine is cheaper. Consider using pressure-treated pine if you’ll be leaving the bench outside. All of these are available at home centers and lumberyards. But make sure to pick straight boards with at least one nice-looking side. You can hide a few minor defects on the back or underside of the bench. Also, avoid boards with large knots, which will weaken key parts and make it harder to cut the notches.

When you get your materials home, cut the pieces to size using the Cutting List below. Many of the parts, like the 1 x 1-in. slats for the grate and the 2-1/2 in. wide legs, have to be cut the length of the board. This operation, called ripping, is possible with a circular saw, but it’s much quicker, easier and more accurate with a table saw.

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Make tight-fitting joints for a strong bench

Photos 1 and 2 show how to notch the legs for the horizontal cross members. Notching looks tricky, but it’s simple if you follow these key steps: First clamp each pair of legs together, and using dimensions from Fig. A (in the Additional Information), mark the lower edge of each notch. Use a square to draw lines across the boards at these marks.

Then align the corresponding horizontal board with this line and mark along the opposite edge to get an exact width. Using the boards in this manner to mark the width of the notch is more accurate than measuring.

When you saw the notch, cut to the waste side of the pencil line, leaving the line on the board. You can always enlarge the notch or plane the board to fit a notch that’s too tight, but you can’t shrink a notch that’s too wide. Tight-fitting joints strengthen the bench and look better too.

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Assembly is quick once the parts are cut

Photos 3 and 4 show how to assemble the leg sections and connect them to form the bench frame. Before you screw the horizontal pieces to the legs, pick the best-looking side of the boards and make sure it’s facing the front of the bench. (The best sides are facing down in Photo 3.) Drill 5/32-in. clearance holes through the cross members to avoid splitting them and to allow the screws to draw the boards tight to the legs.

Use only one 1-1/4 in. screw to attach parts F and G to the front legs. Center the screw so it doesn’t interfere with the 3-in. screws you’ll be installing to secure the leg assembly (Photo 4). Use a 3/4-in. spacer block (Photo 4) to align the cross members (E) before you drive in the 3-in. screws.

If you’ll be leaving your bench outdoors, use stainless steel screws or corrosion-resistant deck screws. For extra strength and durability, put a small dab of construction adhesive on each joint before you screw the pieces together. To hide the 3-in. screws that secure the front legs, use a 3/8-in. brad point drill bit to drill 1/4-in. deep recesses before you drill the 5/32-in. clearance holes. Then glue 3/8-in. wood buttons into the recesses after you screw the parts together. Keep a framing square handy as you assemble the leg sections and bench frame and use it to make sure the assemblies are square before you tighten the screws.

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Complete the assembly

Photo 5 shows how to mark and cut the plywood that supports the potting soil container. We used a plastic wastebasket, but any container with a lip will work. Trace the shape on a piece of plywood and then cut the hole a little smaller so the plywood supports the lip.

The bench top is made of 1-in. thick bullnose cedar decking. Join two pieces with cleats to make a removable cover for the dirt container (Photo 7). Glue 1 x 1-in. slats together with water-resistant wood glue to form the grate (Photo 6). Scrape off excess glue before it dries. Then allow the glue to dry overnight before you sand the grate and trim the ends flush. Screw cleats to the bottom of the grate to keep it positioned and allow easy removal.

The width of the end pieces (P) varies, depending on the dimensions of your decking. To determine the width, first center the grate, removable cover and three more boards on the bench top, leaving an equal space on each end. Then measure the distance from the last board to the outside edge of the back leg and cut and notch the end pieces to fit.

Glue 3/8-in. wood plugs into 3/8-in. by 1/4-in. deep recesses to hide the screws that hold the two end pieces (P) and lower shelf boards in place. Sand them flush after the glue dries. Complete the potting bench by notching the 1x8 shelves (Photo 9) and securing them with 2-in. screws through the horizontal 1x4 shelf rails (H). We used black metal shelf brackets to support the ends.

Protect your Bench with a Good Finish

Unfinished cedar has some resistance to decay, but the best strategy is to apply a top-quality exterior finish to keep the wood from cracking, splitting and rotting.

Penetrating oil–type finishes with a small amount of pigment provide a natural look and reduce fading. Finishes that leave a film provide the best protection. Spar varnish or Sikkens are two examples. Take extra precautions to seal the bottom of the legs to keep them from absorbing moisture from the damp ground. For interior use, any good-quality varnish will work.

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