Tiered planter plans, sized to your space

Parts

Cut list

Kerf 1/8″ included. Every cut runs edge to edge.

Steps

• Tape measure
• Speed square
• Pencil
• Drill/driver
• Clamps
• Safety glasses
• Hearing protection
• Dust mask
• Circular saw or miter saw
• Sander, 120 and 180 grit

Underlined words have a short explanation: hover or tap them. All of them are on the glossary page.

1. 1Before you start

   Read every step once, start to finish, before you buy or cut anything. Each step names the parts it uses by letter; the parts list gives their sizes.

   Set up somewhere flat with good light. A pair of sawhorses with a sheet of plywood on top makes a fine work table.

   Wear safety glasses whenever a tool is running, hearing protection for saws, and a dust mask for sanding and for cutting treated wood or sheet goods. Tie back long hair and loose sleeves. Keep children and pets out of the work area.

   • Tip At the store, pick straight boards: hold each one up to your eye and look down its length. Skip boards that bow, twist or have big knots near the ends.
   • Tip Measure twice, cut once. Most mistakes are a misread tape, not a bad cut.

2. 2Cut and label the parts

   Cut every part on the cut list. Cut the longest parts first: if one goes wrong, it can still become a shorter part.

   To mark a cut, hook your tape on the end of the board, make a small V with its point exactly at the measurement, and draw a square line through the point with a speed square. Put an X on the waste side.

   Cut on the waste side of the line, so the blade's kerf (about 1/8″) comes out of the scrap, not your part.

   Write each part's letter in pencil on a face that won't show, and stack the parts by letter.

   Sand the faces before assembly while they're flat and easy to reach: 120 grit, then 180.

   ✓ Lay the parts out and count them against the parts list. Measure a few: if one is off by more than 1/16″, recut it now.

   STOP. Let the saw reach full speed before it touches the wood, keep both hands clear of the blade's path, and never reach under a board you're cutting. Support long boards on both sides of the cut so the blade doesn't pinch.

3. 3Pick the boards and the screws

   Cedar for the planter: look for boards with mostly reddish-brown heartwood. Pale yellow-white streaks are sapwood, which rots years sooner; keep those streaks on the inside or skip the board.

   Pressure-treated pine: read the end tag. Parts that touch soil, sit in wet mulch or go in the ground must say "ground contact"; "above ground" lumber is fine for everything else. New treated boards are often wet and heavy: stack them flat with scrap sticks between them for a week or two in the shade so they dry and stop twisting.

   Sight down each board at the store like a rifle barrel. Skip boards that twist, bow more than about 1/4″ over 8′, or have big loose knots near where you will cut or screw.

   Use exterior screws only: coated deck screws (labelled for treated lumber, "ACQ compatible") or stainless steel. The copper in treated wood eats plain and zinc-plated steel within a few years. Indoor wood screws and drywall screws rust and snap outdoors.

   For food plants, both cedar and modern treated wood (labelled CA or ACQ, not the old green CCA, which hasn't been sold for homes since 2004) are widely used. If you want to be extra careful, staple landscape fabric inside so soil doesn't touch the wood.

   The corner posts are pressure-treated 2×2 rated for ground contact, because the inner ones stand in wet soil; cedar 2×2 would rot there in a few seasons.

   • Tip Buy one extra board of the most-used size. A split or a mis-cut then costs you nothing but a few dollars.
   • Tip Cedar splits easily: predrill every screw within 2″ of the end of a board with a bit about the size of the screw's inner shank.

   ✓ Every board is reasonably straight, and the screw box says exterior, coated for treated lumber, or stainless.

4. 4Prepare the ground

   Pick a level, sunny spot (6+ hours of sun for strawberries) and mark out 36″ × 36″.

   Mow the grass short. Rake the spot so the high spots go into the low ones, and check with a level on a straight board.

   Lay flattened cardboard over the grass, overlapping 6″, with all tape and labels pulled off. This sheet mulching smothers the grass and rots away in a season, so roots can grow down into the ground.

   ✓ A level on a straight board reads within 1/2″ across the spot in both directions.

5. 5Build tier 1 (the bottom)

   Lay two corner posts (C) flat, outside edges 33″ apart.

   Screw a front board (A) across them, the top edge flush with the post tops and the ends sticking out 1 1/2″ past each post. Two 2 1/2″ deck screws per board end, predrilled.

   Make a second panel the same way for the back.

   Stand the panels up and fit the side boards (B) between them against the posts, two screws per board end.

   • Tip Build every tier before you fill any. It is much easier to square an empty frame on the driveway.

   ✓ Outside it measures 36″ by 36″, and the two diagonals across the top match.

6. 6Build tier 2

   Lay two corner posts (F) flat, outside edges 21″ apart. These posts are 11″ long because they reach down through the soil of the tiers below to stand on the ground.

   Screw a front board (D) across them, the top edge flush with the post tops and the ends sticking out 1 1/2″ past each post. Two 2 1/2″ deck screws per board end, predrilled.

   Make a second panel the same way for the back.

   Stand the panels up and fit the side boards (E) between them against the posts, two screws per board end.

   ✓ Outside it measures 24″ by 24″, and the two diagonals across the top match.

7. 7Build tier 3 (the top)

   Lay two corner posts (I) flat, outside edges 9″ apart. These posts are 16 1/2″ long because they reach down through the soil of the tiers below to stand on the ground.

   Screw a front board (G) across them, the top edge flush with the post tops and the ends sticking out 1 1/2″ past each post. Two 2 1/2″ deck screws per board end, predrilled.

   Make a second panel the same way for the back.

   Stand the panels up and fit the side boards (H) between them against the posts, two screws per board end.

   ✓ Outside it measures 12″ by 12″, and the two diagonals across the top match.

8. 8Stack and fill

   Set the bottom tier on the cardboard and check it with a level on each side. Dig the high corner down rather than packing soil under the low one.

   Fill it to the top with a mix of half potting mix and half compost, firming it lightly with your hands.

   Set tier 2 on top, centred: measure 6″ from its outside to the outside of the tier below, on all four sides. Push or dig its posts down through the soil until they stand on the ground and the tier sits flat at 5 1/2″ up.

   Fill it, then repeat for each tier up to the top. In all you need about 5.1 cu ft: 4 bags of 1.5 cu ft.

   • Tip Soil settles a few inches over the first month of watering. Top it up so every ledge stays full to the boards.

   ✓ Each ledge is 6″ wide all the way round, and a level laid on the top tier reads level.

9. 9Protect it from the weather

   Decide how you want the planter to look in five years. Bare cedar and bare pressure-treated wood both weather to silver-grey and still last many years; doing nothing is a real option.

   To keep the colour, use an exterior oil or semi-transparent stain: brush it on, let it soak in 15 minutes, then wipe off whatever is still shiny. Renew it every one or two years. Avoid clear varnish or polyurethane outdoors: sun cracks the film, water gets under it, and it peels.

   Pressure-treated wood must dry before any stain or paint. Sprinkle a few drops of water on it: if they bead up, wait; if they soak in within ten minutes, it is ready. This can take a few weeks to a few months.

   Leave the inside of anything that holds soil for food plants bare. Finish only the outside faces and the top edges.

   • Tip Finish on a dry day above 50°F with no rain forecast for 24 hours.
   • Tip Oil-soaked rags can catch fire on their own as they dry. Lay them flat outside to dry or keep them in a sealed metal can of water.

   ✓ The finish is dry to the touch everywhere, with no wet or shiny puddles in corners.

10. 10Plant and water

    Plant strawberries or herbs about 8–10″ apart along each 6″ ledge, and something taller or trailing in the top tier.

    Water the top tier slowly. Water soaks down through the whole pyramid, because every tier's soil touches the ground and the soil below. The bottom ledges stay wetter than the top, so put thirsty plants low and herbs like thyme and rosemary high.

    ✓ After watering the top, push a finger 2″ into the bottom ledge: it feels damp.

11. 11Finish

    Ease every sharp edge and corner with 120-grit sandpaper so nobody gets a splinter.

    Sand all over with 180 grit, always along the grain (the direction the wood fibres run). Scratches across the grain show through stain.

    Wipe off the dust with a barely damp rag and let it dry.

    Outdoors, use an exterior finish: a penetrating deck oil or exterior stain, or primer and exterior paint. Leave cedar bare to weather silver if you like. If it holds soil for food plants, leave the inside unfinished.

    Let it dry for the time on the can before using it.

    • Tip Try your finish on a scrap of the same wood first: stain looks different on every board.