Care & Feeding of Your Worm Bin

Care & Feeding of Your Red Wiggler Worm Bin

Making a good home for your worms (Eisenia fetida): Worms tend to vote with their setae (bristles that aid in worm movement through soil). If conditions are not good, they will mount a mass exodus from your bin.

Happy worms need darkness, air, moisture (but not too much) and appropriate food.

1. Make sure your worm bin has adequate ventilation (holes for air to get in), but keep in mind that worms prefer their home to be mostly dark. Small holes spread out through a cover provide air and limit the amount light getting into the bin.

2. You can regulate the moisture levels of your bin primarily through drainage and bedding management. Moisture will accumulate in your bin from condensation and from water content of the food scraps you add. Make sure the bottom of your bin has holes for drainage of excess liquid. You can place the bin on a tray or inside another bin to contain leakage. A handful of perlite or pebbles will help worms climb back into the bin from drainage tray.

3. Bedding substrates such as shredded newspaper and coir (coconut fiber) will retain moisture and provide a place for worms to tunnel. Bedding should be about as moist as a wrung-out sponge. If the bedding is too dry, you can add bits of wet newspaper or a gentle mist of water from spray bottle. (Do not just dump water into your bin!) If bedding is too wet, you can add dry pieces of newspaper or paper board to absorb excess moisture. Consistently super-wet, poorly drained bedding will create stinky, anaerobic conditions that are not optimal for human noses or for worms.

4. Red wiggler are excellent eaters. However, they are very small and they do not have teeth. Food added to the bin should primarily be plant-based and cut into small pieces. One pound of worms can eat about ½ a pound of food per day.

Foods worms like (not exhaustive):
• Apple cores (really, any fruit besides citrus)
• Banana Peels
• Vegetable peels/tops/seeds
• Tea bags (remove string/staple)
• Coffee grounds (they’ll eat the paper filter too, but it takes longer if not shredded)
• Plain oatmeal
• Moldy bread
• Finely crushed eggshells (in small quantities to add “grit” to worm gizzards)

Foods to avoid:
• Citrus (peels or fruit). I’m not sure if it’s the acidity or the fungicide residue on peels, but worms really dislike these.
• Large chunks of things. Worms need lots surface area to be able to scrape mushy, decaying bits off your food scraps. If you throw in a whole apple, it will take much longer for worms to consume it. An apple cores with lots of nooks and crannies will go much more quickly.
• Meat and Dairy items. Generally, it’s good to avoid animal protein-based scraps in your worm bin because they release smelly compounds as they decompose and can attract predators to your bin.
• Fats and oil also produce a strong smell as they decompose.
• Cruciferous vegetables. This is a personal preference. The worms don’t care (they’ll eat them!), but these Brassicas (cauliflower, broccoli, cabbage, kale, etc.) also tend to be smelly as they decompose in your bin.
• Avoid adding too much food to the bin at once. Excess food will start to decompose (often anaerobically), so it can be very stinky. Also, be mindful of the moisture content of food scraps.

Other happy worm home tips:
• Keep worm bin out of direct sunlight. Eisenia fetida can handle temperatures from 40 deg F- 85deg F, easily. If it’s warmer or colder than that, consider bringing worms into a garage or other protected place. I keep my bin in my living room year round.
• You will most likely find fellow travelers (fly larvae, other insects) in your bin, especially if it is outside. Most of these are harmless.
• Happy worms produce dark brown worm castings (worm poop.) These castings should smell like soil and are safe to put directly into garden soil or houseplants.
• Very happy worms will produce baby worms. You can tell this by spotting small, yellowish cocoons in your worm bin, as well as tiny striped worms.