Temperature and Moisture in the Bin
Redworms can survive a wide range of temperatures
(40-80°F), but they reproduce and process food
waste at an optimum bedding temperature range of 55-77°F.
The worms should never be allowed to freeze. Bins
kept outside may have to be insulated with straw in
the winter to keep the worms from freezing. Portable
bins can be kept by a hot water heater in the garage
during the winter to keep them warm.
The bin contents should be kept moist but not soaked.
Do not allow rainfall to run off a roof into the bin.
This could cause the worms to drown. A straw covering
may be needed in exposed sites to keep the bin from
drying out during hot summer weather.
Maintaining the Bin
Food scraps can be continually added to the bin
for up to 2 to 3 months, or until you notice the bedding
material disappear. When the bedding disappears, harvest
the worms and finished compost, then refill the bins
with new bedding material.
Overloading the bin with food wastes can result
in foul odors. If you notice these odors, stop adding
the waste until the worms have a chance to catch up.
Overly moist food waste and bedding also cause odors.
To relieve this problem, fluff up the bedding to add
air and check the drainage holes. As a general rule
of thumb, keep the bedding material moist, but never
soggy. Make sure the food waste is buried properly
in the bedding. Exposed food wastes can attract fruit
flies, house flies, and other pests. Keeping the bin
covered with straw or moist burlap also deters these
Garden centipedes can be a problem in the worm bin,
especially outside. These predators should be destroyed.
Overly wet beds also can attract the earthworm mite,
which may cause the worms to stop eating.
Harvesting the Compost and Worms
There are three basic ways to separate the worms
from the finished compost. One way involves moving
the finished compost and worms over to one side of
the bin and adding new bedding material and food waste
to the other side. Worms in the finished compost should
move over to the new bedding with the fresh food waste.
The finished compost can then be removed.
A second way to remove the worms is to build a small
harvester frame of 2 x 4s with a 3/16-inch mesh bottom.
Place the worm compost on the frame and sift the worms
out. Larger pieces of compost can be returned to a
new batch of bedding and worms.
The compost also can be placed in small piles on
a tarp in the sun (or under bright lights inside).
Because worms don't like light, they will wiggle to
the bottoms of the piles. After waiting 10 minutes,
remove the upper inch or more of finished compost
from each pile until you run into the worms. Allow
the worms to again wiggle to the bottom of the pile
and repeat the process. Combine whats left of the
small piles into one big pile and again repeat the
process. You should eventually end up with a pile
of finished compost and a ball of worms. The worms
can be added back to a new bin of bedding and food
waste. Larger worms also can be used as bait for fishing.