72″ × 30″ elevated planter plans

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
• Miter saw, or circular saw in two passes, for 4×4 posts
• Staple gun
• 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.

   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. Plain steel reacts with the tannins in cedar and leaves black streaks running down from every screw. 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.

   • 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. 4Build the two end frames

   Lay two legs (C) flat on a garage floor or driveway, 27″ apart outside to outside, tops even.

   Lay 2 end boards (B) across them. The top board's top edge is flush with the leg tops; the others sit tight under it. The board ends line up with the outside faces of the legs.

   Predrill and drive three 3″ screws through each board into each leg, in a line about 1 3/4″ from the board end so they hit the middle of the leg.

   Screw an end stretcher (I) across the same face with its bottom edge 4″ above the leg bottoms: two 3″ screws into each leg.

   Build the second end frame the same way.

   • Tip Clamp the board to the legs before drilling so it can't creep while you screw.
   • Tip Put the best-looking face of each board out. Any pale sapwood streaks go on the inside, where the liner will cover them.

   ✓ Measure the two diagonals of each frame, corner to corner. They match within 1/8″; if not, push the long corner in before the last screws go in.

5. 5Join the ends with the long boards

   Stand the two end frames up, end boards facing out, 72″ apart outside to outside. A helper or two clamps holding a long board across the top keep them standing.

   Screw the long side boards (A) across the front and back. Their ends cover the ends of the end boards, flush with the outside. Three 3″ screws into each leg per board, predrilled.

   Screw the long stretchers (H) on both sides at 4″ up, two 3″ screws into each leg.

   • Tip Work on a flat floor. If the frame rocks, loosen the screws on one long side, press the high leg down, and re-drive them.

   ✓ The top is square (both diagonals across the top match within 1/8″) and the frame stands on a flat floor without rocking.

6. 6Fit the floor cleats

   The cleats are the ledges the floor sits on, and they carry all the soil. Set each long cleat (D) inside a long side, between the legs, its bottom flush with the bottom edge of the lowest board.

   Predrill and drive 2 1/2″ deck screws through the cleat into the board every 6″, staggered high and low so the screws don't split it.

   Fit the end cleats (E) the same way inside each end, between the legs.

   ✓ Run your hand along the bottom edge: the cleats and boards are flush all the way round, and no screw tip pokes through the outside.

   STOP. Don't skip screws here. The cleats hold up hundreds of pounds of wet soil; one screw every 6″ is the minimum.

7. 7Lay the floor

   Drop an end floor slat (G) between the legs at each end, resting on the end cleat. Two 2 1/2″ deck screws at each end down into the cleat.

   Lay the 15 floor slats (F) across the box on the long cleats, starting tight against the legs at one end, with 11/16″ gaps between them. Two deck screws into the cleat at each end of every slat.

   The gaps are the drainage holes. Water has to get out the bottom or the roots drown and the wood stays wet.

   • Tip Cut a scrap 11/16″ thick as a spacer and drop it between slats as you go.

   ✓ The gaps are even (about 11/16″) and the last slat ends tight against the far legs.

8. 8Add the lower shelf

   Lay the 15 shelf slats (J) front to back across the top edges of the two long stretchers, between the legs, spaced like the floor slats.

   Predrill and drive one 2 1/2″ deck screw down through each end of every slat into the stretcher edge.

   ✓ The shelf doesn't flex when you press the middle, and nothing hangs past the front of the frame.

9. 9Line the box

   Cut landscape fabric to cover the floor and run up the four sides to about 1″ below the rim. Fold the corners like wrapping a gift rather than cutting them.

   Staple it to the inside faces every 6″ along the top edge and at the corners.

   Use fabric, not plastic, on the bottom: fabric lets water out and keeps soil in. Plastic on the floor turns the box into a bathtub.

   ✓ Water poured on the fabric drains through it, and no bare wood shows on the floor.

10. 10Protect 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.

    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.

11. 11Place it and fill it

    Move it to its final spot now: full, it weighs about 860 lb. Pick a spot with 6–8 hours of sun for vegetables.

    On a lawn or soft ground, set each leg on a concrete paver so it can't sink; check level front to back and side to side with a level on the rim.

    Fill with potting mix, not garden soil (dirt packs hard in a box). You need about 8.6 cu ft: about 6 bags of 1.5 cu ft.

    Water it slowly until water drips from the bottom, top up the mix where it settles, and plant.

    • Tip A layer of compost mixed into the top few inches each spring replaces what the plants used.

    ✓ The rim reads level both ways and water drips out of the bottom within a minute of watering.

12. 12Finish

    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.