What size worm bin should I have?
To figure out the bin size you need, you must first
determine the amount of food waste your family
generates in 1 week. Your worm bin must contain
1 cubic foot of space for each pound of kitchen
waste. Note that this does not mean that the bin
would always be full, but rather that it would provide
ample space for worms to work at the right moisture
and oxygen levels.
You’ll need approximately 1 cubic foot of bin
space and 1 pound of food waste for each pound of
worms you maintain. (There are about 1,000 worms
per pound.) Be sure to follow this rule to avoid
an overloaded or undernourished system. Too
much food may result in overfeeding and harmful
anaerobic conditions for the worms. Too little food
slows the worms’ growth and reproduction and
contributes to their demise.
A 14-gallon worm bin measuring 1 foot deep
by 1 foot wide by 2 feet long (1' x 1' x 2') gives you
2 cubic feet of volume, space for 2 to 2½ pounds of
worms (see figure 1). A system this size can process
2 pounds of kitchen waste per week, approximately
what the average family of two or three produces.
A family of four to six would need a larger bin—
6 cubic feet (1' deep x 2' wide x 3' long)—and more
worms (up to 6 pounds) to process about 6 pounds
of kitchen waste per week.
Notice that in both cases the container depth
stays the same. Because red wiggler worms dwell
near the surface of the soil in nature, their survival
in a worm bin requires that the bin space be no more
than 1 foot deep. This allows for healthy aerobic
conditions in the worm bin habitat.
Make sure to prepare the bin before your worms
arrive. Don’t worry if your measurements or
methods are not exact. The worms won’t notice!