Vermicomposting uses specific species of epigeic worms, such as Eisenia fetida (Red Wiggler or Tiger Worm), to break down organic waste. These worms naturally thrive in decaying surface matter and rich organic environments like compost and manure. Red Wigglers are small, reddish-brown worms that remain near the surface where their food source is abundant. Understanding the nutritional needs of Red Wigglers is crucial, as their enclosed bin environment means they cannot escape unsuitable conditions. This guide provides an approach to their nutrition, ensuring a healthy bin and efficient waste processing.
The Ideal Diet
Worms primarily consume microorganisms and decaying organic matter, not fresh scraps. The food provided must first be consumed by microbes and microbially-decomposed before the worms eat it. Therefore, their diet should mimic the decaying plant material found in nature.
The bulk of their diet should be fruit and vegetable scraps, which they readily consume. Acceptable items include melon rinds, banana peels, apple cores, and most non-acidic vegetable trimmings. Used coffee grounds and tea bags (with staples removed) are also suitable, providing nitrogen balanced by the carbon in their bedding material.
Shredded paper, cardboard, and coconut coir serve as both bedding and a carbon source that the worms will consume as it breaks down. Reducing the particle size of food scraps by chopping or blending is highly beneficial. Smaller pieces allow microbes to colonize the material faster, speeding up decomposition and making the food more accessible.
Materials to Never Include
A healthy worm bin maintains a neutral pH balance, typically around 7.0. Materials that drastically alter this environment should be avoided. Citrus fruits, including peels and juices from oranges, lemons, and limes, are too acidic and can compromise the worms’ health. Large quantities of other acidic foods like tomatoes and pineapples should also be limited or excluded for the same reason.
Meat, dairy products, and oily foods must be kept out entirely. When these items decompose, they quickly go rancid and create foul odors, attracting pests like flies and rodents. The breakdown of proteins and fats can also lead to anaerobic, oxygen-deprived conditions, which are toxic to the worms.
Other Harmful Items
Spicy peppers contain compounds that irritate the worms’ soft skin. Excessive salt, often found in processed foods, is harmful because it dehydrates the worms. Additionally, avoid lawn clippings or food scraps treated with pesticides or herbicides, as these chemicals are toxic to the worm population.
Monitoring and Feeding Schedule
The most effective rule is to only add new food once the previous batch is mostly consumed. Overfeeding is a common mistake and is significantly more dangerous than underfeeding, as worms can survive on their bedding for a week or more if necessary. When starting a new bin, feed conservatively, such as 10% of the worms’ body weight, and observe the consumption rate.
A foul, sour smell indicates overfeeding, which leads to anaerobic decomposition and excessive acidity. If uneaten food is visibly piling up after a week or two, the worms are struggling to keep up. Stop feeding immediately and gently aerate the bedding to introduce oxygen.
Implement a rotational feeding strategy by burying food in different zones of the container. This prevents food accumulation and helps deter pests like fruit flies, which are attracted to surface food.
The bedding should maintain a moisture level similar to a wrung-out sponge. If the bin becomes too wet, which often happens with high-moisture foods, add dry, shredded paper or cardboard to absorb the excess liquid.