A worm composting unit is a system with five elements: a physical structure,
bedding, redworms, food, and maintenance procedures. Physical structure refers
to a box or bin. This can be a self-made wooden box, or a plastic box bought
from a retailer.
The usual box size is one foot high, two feet wide and three feet long. Be
sure to have small air holes in the bottom for aeration. A black plastic sheet
with air holes is also needed to cover the bedding, since worms are
light-sensitive.
For apartment dwellers, a plastic box might be the answer. This can be
purchased from a worm supplier or retailer, which you can find in the classified
section of popular nature magazines. My plastic box is 12 by 12 by 18 inches
with an aerated lid. A plastic box will last longer than a wooden box, which
might be a consideration for some people.
This box can be kept in the basement, kitchen, a spare room, or on the patio.
Outdoor composting is possible from spring through fall. In winter, however, a
covering of vegetable matter and snow is necessary to keep the worms from
freezing. This makes it difficult to add fresh material, so winter composting is
best done indoors.
After you have built or bought a box, you must prepare the bedding. The best
bedding is a mixture of shredded newspapers and corrugated cardboard, grass
clippings, leaf mold, well-rotted pig, chicken and cow manure, and small amounts
of soil. Never use human wastes in the bedding, since this can lead to disease
for both worms and people. A specially prepared dry bedding can also be
purchased from worm retailers.
As for worms, these are found in gardens under rotting vegetation, and under
manure piles on farms. The little redworms are surface feeders, turning waste
materials into nutrient-rich vermicompost. Worms can also be purchased from
retailers for about $30. per pound.
If you buy worms, they will be sent by priority post or overnight courier.
Immediately upon receiving the worms, pick out the dead ones. Add water to the
prepared bedding, and place the worms on top. In general, the dry bedding should
be moistened with a 3:1 ratio of bedding to water.
All worms require oxygen, and produce carbon dioxide, just like humans.
Redworms also use microorganisms in the bedding, which help them break down,
digest, and turn waste material into rich vermicompost.
Temperatures below 50 degrees Fahrenheit (ten degrees Celsius), or above 84
degrees F (28 degrees C) are harmful to redworms. Never place your redworms in
the direct summer sun, and never leave them out in the freezing cold.
While some fluctuation in temperature is to be expected, you should strive
for a temperature range of 55 to 75 F, or 13 or 25 C. These are the best
temperatures for worm health, growth, and feeding.
So now you have a box with bedding and worms. What then do you feed these
little redworms?
Redworms will consume almost any vegetable or fruit waste. Apples and apple
peelings, baked beans, banana peelings, biscuits, bread, cheese, lettuce,
cabbage, celery, carrots, beans, egg shells, cucumbers, pineapple, potatoes,
pizza crusts, other leftover vegetables, and oatmeal are all good food sources
for redworms. Just be sure to chop everything into small pieces.
Note that meats are not included on this list. While redworms will eat meat,
this can lead to an odour problem, which might attract mice and rats.
Potato peelings should be used sparingly, since the cellulose in the peels is
often difficult for worms to break down. Anything too acidic, such as orange or
lemon peels, should also be used sparingly. And never feed worms fat or oils.
As for feeding, once or twice a week will be sufficient. I keep all kitchen
wastes in an old ice cream bucket. There are two people in my household, so it
takes about a week for the bucket to fill with kitchen wastes. A larger family
would likely accumulate greater amounts of waste. About five to ten pounds per
week is normal. This is buried in the bedding, with the second batch of wastes
buried next to the first, and so on.
After 8 to 10 weeks, your bedding will become black, which indicates that the
worms have turned the available wastes into vermicompost. Now is the time to
change the bedding. I change the worm bedding every three months on average –
sometimes less, sometimes more. I keep records of the dates I feed my worms.
This helps me remember when to feed the worms, and when to change the bedding.
To change the bedding, place a piece of plastic on the ground and turn the
worm bin upside down on the plastic. Then put the vermicompost into six or eight
small piles in direct sunlight, or under a bright light. The worms, being
light-sensitive, will go to the bottom of the pile. Simply scoop the
vermicompost and put it into a container. Then, pick up the worms and place them
onto the newly prepared bedding.
Two common problems with worm composting are odour and moisture buildup. If
the bedding smells “ and it shouldn't – this indicates a soil balance problem
which can be corrected by adding limestone, with less feeding. Moisture buildup
indicates overfeeding. If you have moisture buildup – and this is a common
problem – simply cut back on feeding, or change the bedding.
Redworms are prolific breeders with almost unlimited possibilities for
expansion. In reality, however, their numbers are limited by food, space, and
environmental conditions, so you will not be overrun with worms.
Richard Probert is a freelance writer and worm composter who lives in
Agassiz, B.C.
This is one of a
limited number of articles from Natural Life Magazine presented on
this website for free. To read more,
please
subscribe.
