Choose a Bin

Buy a bin or build one out of wood, plastic, an old dresser drawer, shipping crate, or barrel. Your bin needs to be 10 to 16 inches deep, have holes in the bottom or sides for ventilation, and have a snug-fitting lid. To keep rodents out, the holes need to be ¼-inch or smaller. The rule of thumb for bin size is two square feet of surface area per person. An average two-person house would need a bin about 4 square feet, or two bins that are each 1 foot by 2 feet.

Pick a Place

Locate your bin where it will not freeze or overheat—in a pantry, laundry room or basement. Or you can keep your bin in your garden, garage or porch area, and move it inside or insulate it during the winter (see Winter Worm Care).

Make a Worm Bed

Worms like to live under lots of moist paper or leaves. This helps keep them cool and moist, gives them fiber to eat, and prevents fruit flies from getting to their food. To make your worm bed, tear black and white newspapers into one-inch strips, fluff them up, then moisten them with a spray bottle so they are completely moist but not dripping. Fill your bin three-quarters full with this moist bedding. Shredded cardboard, leaves, compost, sawdust, and straw can also be added in as bedding. Do not use glossy paper or magazines. Sprinkle bedding with a few handfuls of soil.

Adopt Some Worms

Compost worms are often called “red worms” or “red wigglers.” Their scientific name is Eisenia fetida. They are different from earthworms and nightcrawlers, which live underground. You can find red wigglers in an old compost pile, get them from a friend’s worm bin, or buy them from a worm farm (call the Rotline for a list of sources). Start with one half to one pound of worms, or two nice big handfuls.

Feed Your Worms

Give your worms about a quart (one pound) of fruit and vegetable trimmings, then leave them alone for a couple of weeks while they get used to their new home. After that, feed your worms about a quart of food scraps per square foot of surface area in your bin per week. To avoid fruit flies and odors, bury food under the bedding.

Maintain Your Worm Bin

Always keep a 4- to 6-inch layer of fresh bedding over the worms and food in your bin. Add fresh bedding at least once every couple months. Keep bedding as moist as a wrung-out sponge. In a plastic bin, add dry bedding to absorb excess moisture. Wooden bins may require adding water occasionally.

Harvest and Use Your Worm Compost

You can start harvesting worm compost two to three months after you set up your bin. Simply reach in and scoop out the brown crumbly compost, worms and all. You can also move the contents of the bin to one side, place fresh bedding and a handful of soil in the empty space and bury food there for a month or two. Harvest the compost after the worms have migrated to the new food and bedding. To keep your worms healthy, harvest at least once a year.

Symptom

Problem

Solution

Worms are dying

Food and bedding all eaten

Harvest compost, add fresh bedding and food

Too dry

Add water until slightly damp; add moist bedding if needed

Extreme temperatures

Move bin so temp is between 55° and 77° F; make sure bedding is adequate

Bin smells bad/attracts flies

Too wet; food scraps exposed

Add a 4- to 6-inch layer of dry bedding and stop feeding for 2 to 3 weeks

Problem Materials

Remove meat, dairy, grease, etc.

Rodents in bin

Bin not rodent resistant; problem materials; too much fruit & vegetable trimmings

Use traps or baits and a rodent-resistant bin (no holes or gaps larger than ¼ inch); remove meat, dairy, grease, etc.; add a 4- to 6-inch layer of bedding and stop feeding for 2 to 3 weeks

Sowbugs, beetles in bin

These are good for your worm compost!