What's inside
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A simple outdoor potting tray keeps loose soil, spilled water, and small tools contained while you work. This weekend project uses exterior plywood, narrow wood strips, and basic screws. The raised edges are high enough to catch potting mix without making the tray awkward to lift or clean.
Contents
Choose a size that suits your workspace
A tray about 24 inches wide by 36 inches long fits a bag of potting mix, a few pots, and hand tools. It also sits on many patio tables and potting benches. For a small balcony or narrow bench, reduce the length to 30 inches; for larger containers, consider 30 by 48 inches, but check that you can carry the finished tray through your door.
This design has 2-inch-high edges and a flat plywood bottom. It is meant for hand potting and short-term storage, not as a watertight basin or a permanent planter. Drainage holes let rainwater escape, but they also allow fine soil and water onto the surface below. Set the tray on a bench or add a removable catch pan if that matters.
Materials and tools
Use 1/2-inch exterior-grade plywood for the bottom and straight 1-by-2 lumber for the sides. A 2-by-2-foot plywood offcut can make a smaller tray; a 24-by-36-inch tray needs a larger panel or a cut from a 4-by-8-foot sheet. Choose exterior-rated screws about 1 1/4 inches long. Avoid interior plywood: repeated damp soil and outdoor humidity can loosen its layers.
You will also need a tape measure, square, pencil, saw, drill, and a 1/8-inch drill bit for pilot holes. A circular saw makes a straight cut on a full sheet; a handsaw or jigsaw is adequate for a small panel. A box of exterior wood screws is a sensible buy if you do not have suitable screws already. For one tray, buying a large specialty kit is unnecessary.
Wear eye protection when cutting and sanding. Support the plywood on a stable surface, and keep hands away from the saw’s cut line.
Plywood and edge options
| Choice | Advantages | Trade-offs |
|---|---|---|
| 1/2-inch exterior plywood | Light enough to carry; affordable and easy to cut | Can flex if the tray is oversized or heavily loaded |
| 3/4-inch exterior plywood | Stiffer bottom for large pots or a wider span | Heavier and usually costs more; unnecessary for a small hand-potting tray |
| 1-by-2 edges | Simple to fit and provide a 1 1/2-inch-high rim when mounted on edge | Offer less soil capacity than taller sides |
| 1-by-3 edges | Catch more loose mix and clippings | Make the tray bulkier and can make scraping soil out less convenient |
For the dimensions below, 1-by-2s mounted on edge create edges about 1 1/2 inches tall, a practical height for ordinary potting. If you want a full 2-inch edge, use 1-by-3s instead. Actual board dimensions are smaller than their nominal labels, so measure the lumber you buy before cutting.
Cut the parts
Make the plywood bottom 24 by 36 inches. Cut two long sides 36 inches long and two short sides 21 inches long, assuming the side boards are 3/4 inch thick. The short pieces fit between the long ones, keeping the finished outside size close to 24 by 36 inches. Check your actual board thickness: the short pieces should equal the bottom width minus twice that thickness.
Dry-fit the sides around the plywood. The edges should sit flush with the bottom’s outer edges, with no large gaps at the corners. If your saw cut wanders slightly, square the corners with sandpaper or adjust the short-side lengths before fastening.
Assemble the tray
Sand the plywood faces and the cut edges of the boards with 120-grit sandpaper. Ease sharp corners so they are less likely to splinter. Lay the plywood flat, position one long side against its edge, and drill pilot holes through the side into the plywood edge, spaced about every 6 inches. Keep the holes centered on the plywood thickness; holes too close to the face can split the ply.
Drive screws through the side into the plywood, then attach the opposite long side. Fit the two short sides between them and fasten each end with two screws into the adjoining long side. Add two or three screws through each short side into the plywood. Do not overtighten: a screw that spins without gripping or breaks through a plywood face will not hold well. If the plywood edge is crumbly, move the hole slightly and use a shorter screw rather than forcing it.
For a 24-by-36-inch tray, add three 1-by-2 cleats beneath the bottom, running across its 24-inch width and spaced roughly 10 inches apart. Screw them into the plywood from above before fitting the sides, or fasten from below with screws that do not penetrate the tray floor. Cleats reduce flex when the tray holds wet mix. They are optional for a smaller tray used on a solid bench.
Add drainage and protect the wood
Drill six to eight 1/4-inch drainage holes through the bottom, spaced evenly and kept at least 2 inches from the edges and cleats. More or larger holes drain faster but can release more soil. If you want the tray to catch water, leave it undrilled and use it under cover; standing water can still seep through screw holes or plywood seams.
Brush on two thin coats of an exterior wood finish, covering the bottom, side faces, and cut edges. Follow the label’s drying and recoat times. A water-based exterior wood sealer is easy to clean up and adequate for occasional potting use. It will not make the tray permanently waterproof, and worn coating should be renewed when water stops beading or the wood begins to look rough.
Let the finish cure fully before putting soil in the tray. Store it under cover when not in use, and empty wet soil rather than leaving it against the plywood for days. Those habits matter more to the tray’s lifespan than applying a thick coat of finish.
Check the tray before use
Set the tray on a flat bench and press gently near each corner. If it rocks, check for an uneven surface or a side board that is not square. If the bottom bows under a loaded pot, add another underside cleat or move the tray onto a more supportive bench. Sand any rough edges that catch a cloth, then test with a small amount of damp potting mix before loading it fully.