Everything You Need To Know About Feeding Compost Worms

One of the benefits of worm composting is putting most of a household’s food waste to good use by transforming it into compost. In general, most people know that these food scraps are mainly used as feeds for a certain type of compost worms, depending on the species that you choose to use. However, the truth behind this method is that not all kitchen scraps can be fed to these worms. Like all living organisms, there are various substances and food types that bring more harm than good, even to creatures such as worms.


That’s why this guide aims to give you a better insight on how to properly care for and feed your compost worms. Read on for some helpful tips in keeping your worms happy and healthy as well.


What do compost worms eat?


Compost worms are voracious eaters. However, contrary to popular belief, they don’t actually eat the food waste that you throw in their bin directly. Instead, they wait for microbes to grow and flourish on the food scraps; and once the microbial content is sufficient and high enough, the compost worms will then start eating their fill. Needless to say, the truth behind their diet is that it mainly consists of these microorganisms that are present in organic food waste.


What food should I feed my compost worms?


Compost worms have a big appetite. They like to eat many of the same things that we consume, especially fruits and vegetable scraps that we have in our kitchen. They can be fed a variety of things such as kitchen scraps and organic materials for these creatures aren’t really that picky. Some of the things that you can feed them include fruit and vegetable peels, bread, cereal, pasta, grains, beans, crushed eggshells, coffee grounds, tea leaves and bags, unbleached coffee filters, shredded leaves, dried grass clippings, newspapers strips, cardboard pieces, fine sawdust, dryer lint, and paper towels.


What should I NOT feed my compost worms?


While compost worms are certainly voracious eaters with large appetites, there are also certain substances and food types that may be toxic or harmful for them. Not to mention, you have to be careful of what you put in your worm bin to make sure that you will not upset the balance of the bin system and trigger foul smell in it. For this reason, it is best that you know what you shouldn’t feed your compost worms to ensure they are kept healthy and happy.


Ultimately, you should NEVER feed your worms fatty or processed food such as meat and dairy products. These types of scraps cause strong odors when they decompose, inviting different types of flies and pests in your worm bin.


And while fruits and vegetables are mainly good for your worms, avoid giving them citrus fruit scraps. Worms can tolerate a wide range of pH. However, exposing them too much to acidic substances can be bad for them. As much as possible, limit the number of citrus fruit scraps that you add into the bin. Small amounts of scraps from oranges, limes, lemons, and grapefruits are acceptable, but remember not to overdo it.


Onions, on the other hand, receive conflicting reports regarding how they affect compost worms in general. Some composters claim they are good for feeding worms, while others do not agree. Nevertheless, it’s your decision if you want to include onions in your compost worms’ diet, but just keep in mind that onions emit a foul smell when decomposing.


Avoid adding oil or oily food in the bin as well. This includes butter too. These substances slow down the composting process. If given in big amounts, they can even stop the composting process all at once. So needless to say, it’s best to keep these type of food away from your worm composter.


Last, but definitely, the most important thing to remember, is salt. Don’t feed your worms salt or salty food. It goes without saying that salt is bad for worms and can, ultimately, kill them., so never put it in your bin.


Summary of What to Feed and Not to Feed Your Compost Worms


What to Feed What NOT to Feed
Fruit Scraps and Peels

Vegetable Scraps and Peels






Crushed Eggshells

Coffee Grounds

Tea Leaves and Bags

Unbleached Coffee Filters

Shredded Leaves

Dried Grass Clippings

Newspaper Strips

Cardboard Pieces

Fine Sawdust

Dryer Lint

Paper Towels

Meat, Poultry, and Fish

Fatty and Processed Food

Dairy Products

Animal Bones

Citrus Fruit Scraps and Peels

Butter, Margarine, and Oil

Mayonnaise and Salad Dressings

Peanut Butter

Oak Leaves

Colored or Glossy Paper Products

Fresh Grass Clippings

Salt or Salty Food

Seasoned Cooked Food


How often should I feed my compost worms?


It is vital that you do not overfeed your compost worms, especially if you have just started with vermicomposting. If you have just set up your worm bin, I know how excited you are to feed your worms immediately. However, it’s actually best if you’ll wait a couple of days for them to settle down in their new environment before feeding them. After a day or two, you can start putting your food scraps in the bin. Be careful not to put too much during the first few weeks. After all, you will need to occasionally check on how fast they can consume the food that you provide. In this way, you will understand the behavior of your compost worms, allowing you to adjust their feeding time according to it.


Nevertheless, you have to be careful not to starve them as well. Compost worms, such as red wigglers, are able to eat half their weight in a day, so it’s best to provide food sufficient enough for the number of worms that you have. If you have 2 lbs of worms, you should give them a pound of food waste per day. If you are not aware of the daily average food waste of your household or how much to feed your worms according to their number or weight, feel free to check our guidelines in knowing how many compost worms you need. All measurements and ratios regarding food waste, composting worms, and worm bins are included in there.


While the method stated above is a general rule, it’s important to still check the bin before adding more food to prevent food waste from piling up in your bin. If you check on the bin to find the worms wriggling about the last bit of food scrap, it’s a sign that you should put some in the bin again.

Feeding Tip: Prior to feeding your compost worms, make sure that you chop or cut down the food scraps into smaller pieces to speed up the composting process. The smaller the food is, the faster it will be covered by microbes that your crawling friends love to eat.

For more read A Guide to Household Composting

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