Caring for Compost and Garden Worms
What should I feed my worms?
What should I feed my worms?
As pets and livestock go, worms are impressively low maintenance. About all that is required is proper feeding. Some people are inclined to through anything and everything we humans call “waste” onto the compost pile, but that can be dangerous when trying to attract worms and increase their population. Here are some guidelines for feeding worms.
The mouth of an earthworm functions somewhat like a vacuum: a buccal cavity takes in the food; a pharynx sucks the food further in and pushes it through the esophagus. Earthworms do not have teeth; they have a crop and gizzard. The crop stores food while enzymes and bacteria begin to break up the food into pieces small enough to move on to the gizzard. The gizzard grinds up food into even smaller pieces that can be absorbed as they pass through the intestines. What is undigested passes out the anus as the treasured “castings.” Logically, the quality of what goes in affects the quality of what comes out.
The earthworm’s nutritional needs are actually similar to ours. Unfortunately, although the earthworm has a complex digestive system, its system does not produce enough of the enzymes needed in the process of converting protein and carbohydrate into energy or enough acid in its stomach to break down the food into usable forms. Therefore, an earthworm needs external bacteria to help it digest its food. The bacteria begin a process of fermentation in the earthworm’s digestive tract that functions in both pre-digestion and digestion. In fact, earthworms will die from malnutrition even if they have plenty of food if bacteria are not present to process it for them. Ergo, the perfect food is germ-filled, bacteria-laden, rotting organic material and animal manure! However, balance must be maintained because too much fermentation can actually cause the crop to swell and burst (not conducive to live worms). Furthermore, earthworms will convert cellulose and carbohydrates into digestible food faster than they will process proteins, so they need more sugars and starches, less vegetable protein, and no animal protein. Finally, since earthworms have no teeth, their food must be kept moist (think of granny without her false teeth).
An earthworm’s diet is a balance of carbohydrates, fat, protein, and minerals, just like ours. It must be full of bacteria, and even the bacteria must be fed. The best place to start is with your kitchen waste. Vegetable waste is the perfect diet for an earthworm. However, you must have a good balance of “green” waste and “brown” waste. “Green” waste is rich in nitrogen and is basically any fresh, moist, green vegetation. Grass clippings, vegetable trimmings, leafy plants, and even weeds fall into this category. Some “outside-the-box” sources of nitrogen are coffee and tea grounds, shells from eggs or nuts, and feathers. Aged manure (composted at least six months) also counts as “green” waste and is one of the richest sources of bacteria and nitrogen. The nitrogen will also feed your bacteria. “Brown” waste is rich in carbon and refers to the dead, dry materials you would feed your earthworms. Leaves, straw, wood chips, shredded newspaper, corn stalks, and peat moss fit into the category of “brown” waste. At this point, I will not dictate to you the carbon:nitrogen ratio; it depends on the type earthworms you have. A general rule of thumb from a research study published in Environmental Science and Pollution Research International Journal recommends a 6:1 ratio. Another study done by students at the College of Water Conservancy and Civil Engineering at China Agricultural University recommends a 20:1 ratio. You see my quandary in making recommendations. I will, however, dictate what should NEVER be put in with your worms:
- Citrus (the acid will kill them)
- Bananas and other tropical fruit rinds (pesticides on peels; exception is organic)
- Meats and bone (see above about too much protein; also, it stinks)
- Heavily spiced foods (think of their tender skin)
- Garlic (see above)
- Eggs and dairy products (same as meat)
- Fresh manure (must be composted and aged)
- Pet feces
- Beach sand (will shred their tender skin)
- Metal, plastics, chemicals, soaps (for obvious reasons)