Here's a win-win weekend project that will help you turn food waste into garden compost using red wiggler worms. Build a wooden worm bin similar to ones used by Anson Biller, manager of Taproot Farm at Sebastopol-based Permaculture Skills Center.
Or modify a plastic storage bin, a system used by Rick Kaye, founder of the Healdsburg-based Compost Club. Both are good choices for people without enough room or sunlight for traditional composters.
Building a wooden worm bin
Electric or battery-powered drill
1/8-inch and half-inch drill bits
1 pound 2-inch-long No. 10 galvanized Phillips-head deck screws, or 8d galvanized nails
Measuring tape, pencil and straight-edge
Handsaw or power saw
Pry-bar or wood chisel to remove pallet slats
two 3/4-inch x 5-1/2-inch x 30-inch pallet boards
two 3/4-inch x 5-1/2-inch x 28-1/2-inch pallet boards
Two 30-inch x 30-inch sheets of 1/2-inch or 5/8-inch plywood (many lumber yards can cut to size)
1 sheet 28-1/2-inch x 28-1/2-inch x 1/4-inch galvanized hardware cloth
34-inch x 34-inch weed-block cloth
4 12-inch x 12-inch cinder blocks
Note: Since recycled wood can be brittle, screws minimize wood splitting and maximize holding power.
Assembly: Butt the two 28-1/2-inch boards flush with the ends of the two 30-inch boards (measure the outside dimensions to confirm the 30-inch x 30-inch outside dimension).
Mark a vertical center line about 3/8-inch from the end of the boards to ensure the screws are centered.
Pre-drill two pilot holes using the 1/8-inch drill bit before attaching the screws. Then drill a series of ventilation holes 4 inches apart along the top inch of each side. Attach one 30-inch plywood sheet to the bottom with one screw every 6 inches.
Drill half-inch drainage holes on a 4-inch grid in plywood bottom. Insert a sheet of half-inch galvanized hardware cloth on top of the plywood and line the sides with weed-block cloth to minimize moisture wicking.
Use the second piece of plywood for an easily removable top. Be sure to drill ventilation holes on a 3-inch grid, using the 1/8-inch drill bit. Set box on cinder blocks for ventilation and rodent control.
Bins can be stored in any available nook or cranny out of direct sunlight. Choose a cool location to keep temperatures between 55 and 85 degrees F. Too cold, you will slow the worms' activity. Too hot, you play havoc with their health.
Making a plastic storage container: With a child often serving as a family's chief worm farmer, plastic bins may be easier to handle when full of mature worm-castings. Kaye's design is an ideal "entry level" project.
Materials and tools required:
Two 1-foot by 2-foot plastic boxes, dark colored
1/4-inch and 1/16-inch drill bits
Four 12-inch x 12-inch cinder blocks
Assembly: The only necessary modification is drilling ventilation holes on the sides and top and drainage holes on the bottom.
Turn both boxes upside down and drill 1/4-inch holes on a 3-inch grid to provide drainage. On each of the four sides, drill a series of 1/16-inch holes spaced about 1-1/2 inches apart.
On just one of the tops, drill about 40 ventilation-holes using the 1/16-inch inch bit. Do not drill holes in the second lid, as it will be used as a drip pan under the bottom box when it is set on cinder blocks.