How to Build an Elevated Wooden Planter Box

This simple DIY garden planter is designed for minimal waste and cost, and is easily customizable.

By: Dan Lipe

Photo By: stevanovicigor / Getty Images

Photo By: vgajic / Getty Images

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Photo By: Joey Kotfica / Getty Images

Elevated Wooden Planter Box

This classic wooden planter is designed to hold upward of 400 lbs, which should be more than enough for wet soil and plants. Tailored to create a larger or smaller box, the real structure of this planter is provided by the base.

Tools and Materials Required

Saw (mitre, table, jig, circular or hand saw) — chisel — drill + bits — screwdriver — staple gun — clamps — (1) 4x4 x 8' cedar — (10) 1x6 x 8' cedar — (4) 2x4 x 8' cedar — 1-5/8" deck screws (1 box) — 3" deck screws (1 box) — landscape fabric — staples.

Cut List

Exact measurements of wood pieces may vary based on the size of your box. For this project, we used the following pieces of wood: (4) 1x6 x 6’ — (6) 1×6 x 22" — (6) 1x6 x 73-1/2” — (2) 2x2 x 22” — (4) 2x2 x 13”  — (2) 2x2 x 14-1/2" — (4) 4x4 x 23-3/4 — (2) 2x4 x 6’ — (4) 2x4 x 19-3/8”

Prep 2x2s

Cut one of the 2×4s into 2×2s. You can get two 8’ lengths plus a little sliver from the middle. Doing this first can save you a little time later. The 2×2 will be used as structure for the box.

Create the Box Bottom

For the bottom of the box, lay all the 1x6s on the ground. Look for splits, knots, warping, etc. Pick out the worst four, these are going to be the bottom of the box. Cut the four to 6-foot lengths. While you’re at it, cut two of the 2x4s to 6-foot lengths and set them aside. These will be used later to make the stand.

Measure the Width of the Bottom

Lay the four bottom boards next to each other and measure the width of them. Together they should be around 22”. This measurement will be end boards and the end brace.

Create Box Ends

Take the measurement from the previous step (in my case 22”) and cut that much from each of the remaining six boards. These will be the box ends. While you’re at it, cut two pieces of the 2×2 (from earlier step) at the same length.

Start the End Panels

You’ll need two of the end pieces and the two braces for this step to start the end panels. The braces will be attached 2-1/4” from the edge of the 1x6s (we’ll call this the bottom). Using clamps to hold them together, pre-drill two holes 6” from the end and attach with 1-5/8″ screws.

Make Corner Braces

Lay each of the assembled pieces on the flat side alone with two more of the end pieces. Measure the distance from the top of the brace to the end of the three boards. It should be in the 13-1/8 neighborhood. Cut four pieces of the 2×2 to this length, these will be the corner braces. Attach them along the edges of the 1x6s by pre-drilling and screwing the 1×6 to the bracing.

Finish the Ends and Join With the Bottom

Strengthen the joint between the bottom brace and the corner braces by drilling up through the bottom and driving a 3” screw into each corner. You now have the two box ends. Attach the four bottom boards to the ends by pre-drilling and 1-5/8” screws. I used clamps to hold the end panels to my bench for this part.

Create the Box Sides

Measure the outside length of the box. It should be around 73-1/2”. Those six remaining long pieces of 1×6? Cut those to this length. Attach the sides to the corner braces. See that overhang in the picture? DON’T do this. I actually left sides long and cut them flush after assembly. What ended up happening for me is I ended up with some sloppy ends.

Attach the Sides

Attach the sides to the bottom boards using 1-5/8” deck screws. My method: locate the center and pre-drill holes every 12” outward from center. Pop an extra screw in each of the corners to attach the sides to the ends.

Attach Side Braces

Set the assembled box on its bottom. On the inside of the box, measure from the bottom to the top. You should get a measurement of around 14-1/2. Cut 2 pieces of 2×2 to this length. Attach these vertically inside the box in the middle. Flip the box over and drive a 3” screw through the bottom into the side brace.

Cut Legs

Cut the 4×4 post into four 23-3/4″ lengths. Why? So you can get four legs out of a single 4×4.

Arrange Legs

Put the legs in a nice little stack like this, simulating their placement on the base. I like to rotate them so that the best sides are outwards. Mark a triangle on the bottom to indicate their position in the group. Note which faces will be the outside edges.

Make Notches

Mark the locations some notches. The notches will mate up with the 2×4s, so they will be the height and depth of a 2×4.

Cut the Outside Edges

Set your saw to the depth of a 2×4 and make a series of cuts on the outside edges (outside in relationship to the stack in the previous step).

Make a Series of Cuts

Make a series of cross cuts to get the party started. A table saw is more efficient than a circular saw. A band saw might be even better.

Chisel Away What is Left

Use a chisel to remove what is left. It doesn’t have to be absolutely perfect, so don’t sweat a little grove here or there. The point is that the weight of the box and soil will pass through the 2×4s into the leg at this point. It will also serve as the foundation for the structure.

Stage the Braces

Take the box and flip it upside down. Remember the 6-foot 2×4s? Place them in the bottom of the box. If they are a little too long, trim a little off. If they’re a tad short, don’t sweat it, not a biggie. What we’re doing here is measuring the space in-between the 2x4s. It should be in the neighborhood of 19-1/4”. Be sure to make the this measurement at the ends of the box as well as in the middle. I found that my middle was slightly narrower than the ends. Cut four pieces to fit a little loosely in between the 2×4s. Really the easiest way to do this is to put a 2×4 in place, mark it and cut it, custom fitting each to its position.

Add Additional Supports

Add the additional supports 2’ from each end and attach with 3” screws.

Attach the Legs

Lay the sides and end 2×4’s on out in a loose rectangle. Take a leg and turn it upside-down and clamp it into place in a corner of the 2×4’s (the notches you cut out should mate nicely to the 2×4’s).  Check for square. Pre-drill and screw into place using 3” screws. Do the same on the end pieces (clamp, drill, screw).

Add Landscape Fabric

Place the box on top of the stand. Drill 3/4 inch drain holes 12” from each end. Staple landscape fabric into the box and fill it with soil mix.

The Finished Product

It's time to start planting!