The Ultimate Compost Bin

Successful organic gardeners rely on compost to improve soil’s fertility and moisture management, nourish helpful soil microbes, and inoculate against destructive ones. This three-bin system is a compost factory that efficiently pumps out heaps of finished black gold in just weeks, rather than the months you wait for the hands-off approach to work. Made from rot-resistant cedar, our ultimate compost bin features removable front planks, and a clean look that allows for good air movement. You can build it in just a few hours.

What you need:

• Saw
• Drill
• Measuring tape
• 2 boxes of wood screws (2" and 2 1/2")
• Mallet or sledgehammer
• 4' x 4' metal fence posts with screw holes
• Staple gun and staples
• 36' x 3' wire netting (chicken wire or a stronger material with similar-size openings)

Wood:

• Dimensions                   Quantity
• 1" x 6" x 12'                         7
• 1" x 6" x 10'                         9           
• 1" x 2" x 10'                         2
• 2" x 6" x 10'                         2           
• 2" x 6" x 12'                         2           
• 2" x 4" x 12'                         2

Cut list for wood:

• Removable planks: Cut 4 of the 1 x 6 x 12s into 12 pieces, 3'7 1/2" each
• Uprights (for end and middle panels): Cut the 2 x 4 x 12s into 8 pieces, 2'10 1/2" each
• Side slats: Cut the 1 x 6 x 10s into 18 pieces, 4'6" each
• Front and back supports: Cut the 2 x 6 x 12s into 8 pieces, 2'10 1⁄2" each
• Bottom pieces: Cut the 2 x 6 x 10s into 4 pieces, 4'9" each
• Plank supports: Cut the 1 x 2 x 10s into 6 pieces, 2'10 1/2" each
• Back slats: Use the 3 remaining uncut 1 x 6 x 12s
   

Making the End Panels

Step 1.

On a flat surface, place two side slats on top of two uprights. To avoid splitting the wood, drill guide holes first. Attach.

Making the End Panels

Step 2.

Attach third side slat, spaced evenly, to make one side panel.

Making the End Panels

Step 3.

Position front and back supports as shown, placing the assembly on a hard surface (we used one of the planks).                

Making the End Panels

Step 4.

Attach them, screwing into the side slats (above) and also into uprights (see finished photo).  

Making the End Panels

Step 5.

Flipping panels upside down, attach bottom pieces as shown using 2 1/2" screws.

Making the End Panels

Step 6.

Repeats steps 1 through 5 to build the other end panel.

Making the End Panels

Step 7.

To make grooves for removable planks, lay panels flat. Allow one plank’s thickness (plus a little), and attach plank supports to side slots, leaving plank in place as a guide.

Making the Middle Panels

(Build these panels as you did the end panels, with a few exceptions.)

Step 1. Repeat steps 1 and 2 above.

Making the Middle Panels

Step 2.

Flip panels and fasten three more side slats on the other side of both middle panels.

Making the Middle Panels

Step 3.

Front and back supports must be centered perpendicular to the uprights.

Making the Middle Panels

Step 4.

Attach bottom pieces, being careful to screw into the side slats. Use 2 1/2" screws.

Making the Middle Panels

Step 5.

As with side panels, create grooves for planks by attaching plank supports to uprights.

Do this on both faces of the two middle panels, as shown.

Putting It All Together

Step 1.

Balance panels on their front supports. Attach the 3 12’ back slats to both end panel back supports.

Step 2.

Measure 49" from each end to mark where middle panels will go. Attach middle panels with screws, centering marks on back supports.

Putting It All Together

Step 3.

Place bin with bottom pieces on soil and slide four removable planks into each bin to evenly space front supports.

Putting It All Together

Step 4.

Remove planks and pound in metal fence posts.

Putting It All Together

Step 5.

Attach posts.

Putting it all together

Step 6.

Staple wire netting to insides of each bin.

Step 7.

Replace removable planks and you’re done!

How to work the three-bin system:

Fill bin #1, then turn the contents from the full to the empty bin (#2) every few days (the more often, the faster the decomposition). Begin filling the other empty bin (#3) with fresh materials. When bin #3 is full, bin #2 is “finished,” and you have an empty bin (#1) to start the process over.

Keep Reading: What's Your Composting Sign?

Photos: Thomas MacDonald