Feeding your compost worms: The good and the ugly…

Having trouble figuring out exactly what you should and shouldn’t feed your compost worms in order to maintain a healthy worm bin? 

In this blog, I will go over the exact foods which you should feed your compost worms, and more importantly, foods which you should avoid to ensure your worms stay healthy and continue to provide amazing compost.

In this blog: 

• What should you feed your compost worms
• What not to feed your compost worms and why
• How to feed your compost worms correctly for a healthy worm bin

What should you feed your compost worms:

The most important factor here is that worms eat organic matter. To be safe it is better to try not to feed them anything other than that! But they will thrive on some things over others.

All manner of vegetable and fruit peelings, eggshell, tea (bag and all) and coffee grounds provide a king's feast for worms. You can be indiscriminate about these items and your worms will thrive. They will also eat shredded newspaper, egg cartons and cardboard. Worms will also consume human (and pet) hair and nails.

The following include common fruit, vegetable, and organic waste, which you can feed your compost worms, including:

• Fruit and vegetable peels, rinds and cores (including pumpkin, leftover corn cobs, melon rinds, banana peels, fruit and veggie detritus)

• Egg shells, shredded newspapers, egg cartons and cardboard

• Coffee grounds and filters

• Tea bags & leaves

• Aged manure from any vegetable-eating animal (rabbits, horses, cows, llamas, etc.) NOTE: Make sure that you do not use manure that contains deworming medication, which could kill your worms!

 Remember: When feeding worm compost, basically go “green” 

Worms will eat almost anything that you would put in a traditional compost bin. “Green” additions are nitrogen-based (grass clippings, plant cuttings, and fruit and vegetable scraps), but the worm bin also needs “browns” or carbon-based items such as shredded newspaper, copy paper, egg cartons, and cardboard.

What not to feed your compost worms and why:

There are a few things you need to be wary of when feeding worms. The main foods we want to avoid feeding the worm are usually toxic foods which can harm the worm itself, or foods which can disrupt the environment of a healthy worm bin.

Foods such as citrus containing limonene, a substance toxic to worms in anything other than small quantities, should be avoided. Onions and foods from the onion family (leeks, shallots, garlic, chives), meat and dairy in all forms, and pet poop are all foods you want to avoid feeding your worms.

The following include common toxic foods which will harm your worm bin:

• Tomatoes or potatoes

• Worms will eat tomatoes but make sure to break down the seed or you will likely have some tomato sprouts in the bin. The same may occur with potatoes and their eyes spouting before the potato is consumed.

• Meat, dairy, salty or oily products
• Rotting meat, dairy, salty and oily products in the compost bin smells repulsive and tends to attract unwanted pests like flies and rats, therefore you should always avoid adding such foods in your worm bin.

• Pet poop
• Contains toxic compounds harmful to your worms, therefore best to avoid pet poop.

• Citrus, acidic fruit skin (oranges, lemons, limes, grapefruit and pineapple)
• Acidity in citrus peels can kill worms and other microorganisms, which can slow down decomposition rates in your bin. Avoid putting acidic fruit and compounds into your worm bin. 

• Spicy foods: onion, garlic, leeks, capsicums, hot peppers
• Just like spicy foods would irritate the taste buds of humans, the same applies to worms. I

How to feed your compost worms correctly for a healthy worm bin

Cut up larger pieces of fruit and vegetable into smaller pieces before feeding. This aids in the decomposition process.

Depending on the size of your bin, feed the worms between once a week to every two days with about a cup (240 ml.) of food. You may want to keep a journal regarding how quickly your worms consume certain things so you can adjust the timings, amounts, and varieties. Worm bins which are smelly may be an indicator of overfeeding. Make sure you are rotating the areas of feeding in the bin to ensure the worms are being fed and tuck the food 3 to 4 inches under the bedding so the food cannot be infiltrated by pests.

Indications of proper feeding involves analyzing both the condition of your worms and their increasing numbers. If your worms are healthy and growing that is a tell tale sign that you are providing the correct foods in the right amounts.