Buying or Building Your Worm Bin

Building Your Own Worm Bin

A worm bin is very easy to build yourself. At its simplest, it's just a box, made from of wood, plastic, even metal. It can be built from scratch or can be created by modifying a box, bin or large container that once had another use. Those with skills in carpentry may wish make a much more elaborate worm bin, and we encourage everyone to take a paintbrush to your bin, putting on those homey touches.

Size

In order to determine how big a bin you need, you must first find out how much food waste your household produces per week. Save up your food scraps and weigh them.

If you want your vermicomposting bin(s) to handle all of your food waste, then figure that same number square feet for the surface area of the bin. Add a bit more area for good measure, and that will let you handle any occasional extra food waste you produce.

Shape

A worm bin should be shallow, roughly 12"-18" high. The reason is that when the composting material in a bin gets deeper than that, it tends to become compacted and slow down or stop the passage of air. Parts of a bin that receive too little oxygen are going to promote anaerobic decomposition - and that stinks!

Wooden Bins

Use wood that resists decomposition. Cedar and redwood are good choices. NEVER use treated wood. Yes, it resists decomposition, but it also contains poisons that you do not want in your worm bin, or in the finished product.

Exterior grade plywood is often used for the sides of the worm bin for longevity. See resources below for design plans for these bins.

Plastic Bins

Plastic totes make excellent worm bins. Pick one that's large enough to handle the amount of food waste you want to process. Then

1. Provide aeration. Plastic bins tend to hold in moisture, and that can spell trouble if there's not enough aeration. Using a 1/4" bit, drill holes all the way around the bin, two inches from the bottom and two inches from the top. Make the holes 2-3 inches apart.
2. Create a dozen or so drain holes on the bottom of the bin. (Put the bin on top of some boards. You can also create or buy a tray to catch any liquid that falls through, and prevent any messes.
3. Drill holes on the bottom of the bin, so that any excess moisture can escape.

Keep It Dark

Worms are sensitive to light and will remain buried if light enters the worm bin. Since you want worms to be comfortable, provide a lid and build with material that doesn't allow light to pass. A few slits between boards are no problem, just make sure it's fairly dark in there. The worms will thank you.

Worm Bins & The Art of Reuse

Just about any container will work as a worm bin. We've seen bins made from and old dresser drawer, from a night stand and from an army ammo box. A bathtub or utility sink will also work fine as a worm bin.

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What is Vermicomposting | Worm Bin Location
Building your Worm Bin | Set up | Feeding
Basic Worm Bin Care | Troubleshooting
Harvesting Worms and Castings | Food and Organic Compost Tea
Advanced Topics | Earthworm Biology and Production