How to Feed Your Composting Worms
What and how you feed your worms is a big factor in how healthy your worm farm will be.
In short, it is all about balance. Balancing the types of foods you give your worms, and balancing the amount. It is not a precise science, so the reality is you will need to monitor your worms and find that balance through a process of trial, error and love. Get to know your worm farm and its habits and you will be a happy farmer.
This blog is for urban worm farmers – people who have smaller farms where the margin for error is smaller purely because you’re working on a small scale and it’s therefore much easier to get the balance wrong. It all still applies to those living with the luxury of bigger worm farms, but you can afford to take more risks without posing an existential threat to your worm population.
What to feed your worms
The key point here is that worms eat organic matter. Don’t 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 kings 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. And while this one always prompts people to screw up their faces, worms will also consume human (and pet) hair and nails.
What not to feed your worms
There are a few things you need to be wary of feeding worms. Citrus contains limonene, a substance toxic to worms in anything other than small quantities so be careful of disposing of rind in your worm farm; they don’t tend to like onions and foods from the onion family (leeks, shallots, garlic, chives); meat and dairy in all forms are a no-go zone; and pet poo is toxic and should not be fed to your worms.
There are many and varied opinions on what you can and can’t feed your worms and if you are researching multiple sources, you will find data that contradicts the above (pet poo is probably the only ‘food’ in the list that is universally agreed should not be fed to worms). We consider that the above advice is the best approach for small, urban worm farms. That said if you do feed your worms anything from the taboo list, it’s probably not the end of the worm. As we are just about to explain, a big part of your worm farming success will come down to quantity of food in any case.
You should also remember to feed your worms a balanced diet. Too much of one food item (fruit for example) threatens to upset the pH of your farm and degrade conditions. Try to feed your worms a good mix of different food items to balance out conditions. Your worms will be happier for it.
How much to feed your worms
In my opinion, overfeeding your worms is the number one reason why worm farms fail. Overfeeding is easy to do, particularly if you have a new farm and are not yet familiar with how much food your worms are capable of consuming.
Overfeeding can result in bad smells (because the waste rots before the worms can process it), attract flies and other pests, and ultimately result in death if the conditions become unbearable. Any of these issues might be enough for you to throw in towel and bring your career as a worm farmer to an abrupt halt.
But don’t act so rashly! Thankfully, there are some easy tips and tricks that will fix the problem and prevent it from happening again. If you track what you are feeding your worms and monitor the timeframe in which they are consuming food, getting the consumption rate right won’t take long and you will be well on your way to co-existing in harmony with your worms.
The signs of overfeeding are pretty easy to recognize. You will smell it, or notice flies hanging around your farm like a bad smell. You may notice worms ‘trying to escape’ or you may notice that some of your worms are no longer of this world.
If you have overfed your worms, here are some measures you can take to rectify the situation.
1. Remove any rotting food from the farm (don’t be afraid to get your hands dirty, it’s all in the name of the healthy worm);
2. Gently aerate the bedding with a fork to give the farm a healthy oxygen hit;
3. Wait until your worms have consumed all their food before adding more to the pile. This is a good general tip to prevent overfeeding;
4. Chop or blend your food scraps. Smaller pieces makes for faster consumption, so you can compost more of your waste without threatening the health of your farm;
5. Be prepared to experiment with what you feed your worms and how often you feed them. This will allow you to get to know your worms’ eating habits well and really is the key to a thriving farm.
Download Our Helpful Factsheet as a Reminder of the Dos and Don’ts of Feeding Worms