Building Your Own Worm Bin

You can grow your own worms in any sturdy box that is eight to twelve inches deep. Worms love to eat garbage and will produce rich, black humus in exchange. This is very good for your garden! And it helps keep food scraps out of the landfills, and makes the worms very happy!

Step One:

Get a box. You can use any sturdy box that has been discarded. An old dresser drawer or fish tank are possible suggestions. You can also purchase a plastic storage box for a few dollars. Or you can build a box—make one that is twelve inches (12") deep, 24" wide and 36" long. You can make a hinged lid or cover the box with a screen. This is especially important if you have cats. We don't want the cats to use your worms' home as a litter box! This could kill the worms. Drill small holes in the bottom of the box for drainage and to promote air circulation. Ask an adult to help you with any power tools! Place the bin on bricks over a tray or plastic sheet to catch any drips or worm droppings, or keep your worm bin outdoors through the spring, summer and early fall.

Step Two:

Add bedding. The best bedding is old newspapers. This will hold in moisture and provide air circulation. You can also use corrugated cardboard. Shred the newspapers or the cardboard into 1/2" to 1" strips. Avoid colored newspaper—the inks can be harmful to the worms. Moisten the paper or cardboard with water in a big plastic bag, like a garbage bag. The bedding should be moist, but not soggy or dripping—it will feel a little like a damp sponge. If it is too dry, add more water. If it gets too wet, add more shredded bedding.

Fill your worm bin about 2/3 full with the moist bedding. Be sure that it is NOT packed down tightly—your worms will need room to move around, and to get air. Try "fluffing" it a little to add air spaces. Add three to four cups of soil to the bedding by scattering it over the top of the damp bedding. This will help provide nutrients for your worms.

Step Three:

Add worms. The best worms to use are red worms. DON'T use nightcrawlers—they like to tunnel long distances and will die in a worm bin. You can obtain red worms from various mail order companies, or try your local bait and tackle shop. (Or check out this online index of worm farms.) Local nurseries and garden shops often have worms for sale, too. One pound of worms will eat about a half pound of kitchen waste per day. There are 1,000 to 1,500 worms to a pound.

Step Four:

Feed the worms. Worms will eat all kinds of food scraps. You can feed your worms eggshells, coffee grounds and filters, tea bags, onion skins, potato peels, apple cores, leftover pasta, leaves and any kind of vegetable matter. DO NOT FEED THE WORMS MEAT, BONES, OR FATS. Some worm experts say that it is OK to feed your worms cheese, and others disagree. Try to avoid cheese and other dairy products, or use only small amounts. Start slowly, feeding the worms a little at a time until you are sure they are eating all the scraps. If the bin starts to smell bad from rotting food, reduce the amount until your worms can catch up. Spread the scraps in a thin layer on top of the bedding. If the bin is kept in a dark place, or kept covered with a lid, the worms will come to the surface to eat. DON'T PUT ANY OTHER KIND OF TRASH INTO THE BIN. Don't use pesticides near the worm bin, either, or you'll kill your worms. Don't put any manure in the bin, or it will get hot and cook your worms.

Step Five:

Harvest the compost. In three to four months, the worms will have turned almost all of the bedding and food into "worm castings." Worm castings are a rich, black humus that is very good for the soil in your garden and houseplants. Open the bin to the sunlight, or shine a bright light into the bin. The worms will go to the bottom and you can take the humus off the top. Use your hands or a sieve and put any worms back into the bin. Add the compost to the top layer of houseplants or on the top of your garden soil. You can also add it to any soil mixes.

Harvest the compost three or four times a year and keep feeding the worms, and you'll have a perpetual compost-making machine. If you get too many worms for the box, start another one, or add them to your garden.