Vermicomposting uses worms, primarily red wigglers (Eisenia fetida), to break down organic waste into nutrient-rich soil amendments. Understanding what to feed these composting worms is fundamental for maintaining a productive and healthy worm bin. Proper nutrition ensures the worms thrive, allowing them to efficiently convert kitchen waste into valuable worm castings.
Ideal Food Sources for Worms
Composting worms consume a variety of plant-based materials. Fruit and vegetable scraps, such as peels, cores, and spoiled produce like lettuce, carrots, bananas, apples, and melons, are highly suitable. These items are rich in nutrients and break down easily. Worms especially favor softer fruits like bananas.
Coffee grounds and tea bags (without staples) are excellent additions, offering valuable nitrogen and helping to balance the compost’s pH. Crushed eggshells provide calcium, which benefits worm reproduction, and also act as grit to aid their digestion. Shredded paper or cardboard, along with dried leaves, serve as carbon sources and essential bedding material that worms will eventually consume. Small amounts of plain pasta, rice, or bread can be added, provided they are free from oils or sauces.
Foods to Keep Out of Your Worm Bin
Certain food items should be avoided in a vermicompost bin to prevent harm to worms, pest attraction, or unpleasant odors. Meat, dairy products, and oily or greasy foods are not suitable because they decompose slowly, can become rancid, and attract pests. These materials also produce foul smells and disrupt the bin’s environmental balance.
Citrus peels contain high acidity that can upset the pH balance of the worm bin, potentially harming the worms if added in large quantities. Spicy foods, onions, and garlic are generally avoided by worms and can create strong odors. Salty foods, chemically treated items, and pet waste should never be introduced into the bin, as they can be detrimental to worm health or introduce pathogens.
Optimizing Worm Feeding
How and when you feed your worms significantly impacts bin health and composting efficiency. Chopping food scraps into smaller pieces before adding them to the bin accelerates the decomposition process by increasing the surface area available for microorganisms and worms. Freezing and then thawing food scraps can also break down cell walls, making them easier for worms to consume.
Start with small amounts and observe how quickly the worms consume it. Worms can eat about half their body weight in food per day, depending on the worm population and bin conditions. Feedings can occur every two to three days, or when most of the previous food has been consumed, to prevent overfeeding, which can lead to odors and anaerobic conditions.
Burying food scraps beneath the bedding helps deter pests and control odors. Maintain the bin’s moisture level, aiming for a consistency similar to a wrung-out sponge. Too much moisture can create anaerobic conditions, while too little can dehydrate the worms. Regularly adding brown materials like shredded paper or cardboard helps balance moisture and provides a carbon source.