MAKE: Trash Can Composter

MAKE magazine opens in a new tab brings the do-it-yourself mindset to all the exciting projects in your life and helps you make the most of technology at home and away from home. Projects in the magazine range from old-school balsa wood and tissue-paper airplanes to what to do to keep aging high-tech gadgets alive to building autonomous robots from junk.

In this post, MAKE contributor Thomas Arey shares how to make a composter from a trash can.

I like to pick things out of trash cans and reuse castaway items. Here, I repurpose the trash can itself to facilitate recycling organic waste into beneficial compost.

Commercial composting canisters can be costly, but they’re simply a place to allow natural microbial processes to convert waste matter into a dark, fresh-smelling soil. Commercial versions allow air and some water to get in, and sometimes a way to mix.

Most home trash cans fail when part of the bottom wears away, leaving a hole. Such a trash can is perfect for this project, since we’re just going to add more holes anyway.

Step 1: Clean the trash can

• Scrub the trash can thoroughly inside and out to ensure that no inorganic waste remains. If you’re squeamish about this, buy a new one.

• It’s helpful but not necessary to have a lid. If the original lid has gone missing, I’ll leave it to you to come up with another solution.

Step 2: Drill air holes
Use a drill with a 1" spade bit to make air holes. Space the holes about 3" to 4" apart over all sides of the trash can. Drill plenty of holes, but don’t compromise the structural integrity of the trash can. Avoid the corners to maintain the trash can’s strength. Drill holes on the bottom to help with drainage.

Step 3: Start Composting

Theories about composting are as numerous as the holes you have drilled. General rules:

• Keep the compost material damp, not wet.

• Mix brown material (such as leaves) in with green material (such as grass clippings).

• Use uncooked food scraps; no meat.

• Don’t allow pet waste or anything treated with pesticides into your composter.

• Turn the compost material regularly. If your can has a tight-fitting lid, you can lay it on its side and roll it around on the ground.