Vermicomposting isn't for the squeamish, and you've got to be brave to keep worms in your house. That said, a well-managed indoor worm bin is surprisingly sanitary, odor-free and productive. In one to four months, a healthy indoor worm bin will produce rich, nutritious castings that you can use as fertilizer for houseplants or garden beds. You can make your own bin or buy a commercial version, but it's up to you to take care of your worms so they can turn your kitchen scraps into fertile compost.
Design your worm bin. You can purchase a commercial bin, or use an opaque plastic bin or wooden box. For a single user, start with a bin with a volume of 4 cubic feet; add 1 to 2 cubic feet for each additional person in your household.
Drill air holes in a homemade bin. Drill approximately every three inches, starting about four inches from the bottom of the bin. If desired, drill drainage holes in the bottom.
Tear paper into thin strips, and dampen it slightly. Place paper in the bin. Keep adding paper until the bin is nearly three-quarters full; this is referred to as "bedding" for your worms.
Mix a few handfuls of dirt into the bedding. Add 1 lb. of red worms, and leave the bin open at least an hour for worms to burrow into the bedding.
Feeding and Maintenance
Feed your worms vegetarian organic material: all types of kitchen scraps, except meat and meat products. Bury the food under the bedding; worms will seek it out and eat it.
Add bedding regularly: worms will eat paper along with compost. Periodically add handfuls of dirt. This will not hurt the worms but will help them digest.
Check the bin's moisture level daily. If it becomes too moist, it will smell and your worms can become sick and die. Add dry bedding as necessary, or dampen bedding if it feels dry.
Observe the contents of your bin carefully. When the compost is dark brown, crumbly and earthy-smelling, it is ready to harvest. This can take one to four months.
Divide your bin in half, with all the finished compost on one side. Add fresh bedding and scraps to the other side. Worms will begin to leave the finished compost in search of fresh food.
Wait two weeks, then open the bin to bright light. Worms will burrow into the bedding. Remove the finished compost, checking for any stray worms. Your vermicompost is ready to use.
- If you use drainage holes, you will need a tray to catch drippings, and you will need to clear holes regularly to avoid clogs. If you do not use drainage holes, you will need to monitor the moisture in your bin and add dry bedding as necessary.
- Always bury food beneath the bedding to avoid odors.
- Harvest compost when it's mature. It is poisonous for worms to eat, so they will need to be separated from it.
An award-winning blogger, Jessica Blue has been promoting sustainability, natural health and a do-it-yourself attitude since graduating University of California, Berkeley in 2000. Her work, seen in a wide variety of publications, advocates an environmentally-responsible and healthy lifestyle.