Published on May 6th, 2019 | by Sarah Dephillips

Worm Bin Composting – The EASY Guide

Want to start your own worm compost (also known as vermicast) bin, but not sure where to start? You’ve landed in the right place. To the beginner, worm composting can seem a little gross (do I have to touch them?!) or even a little intimidating (what if I accidentally kill all my pet worms?!) but there’s no reason to fear. You can set up an easy, inexpensive worm bin in an hour or two and be on your way to great compost.

Why Worms?

Really the first question we should answer is why compost, but you can read all about that here. So assuming you’ve already made up your mind to compost, why do it with thousands of little invertebrates who eat your food scraps and poop out plant food? First, because it’s easy and fun. But more importantly, because vermicast (worm poop) is considered the most bioavailable organic source of plant food. This means that compost processed by worms will be the most nutritious to plants, because the worms put those nutrients in a form that the plants can take up and process best. By composting with worms, you’re leveraging nature’s symbiotic relationship between food waste, worms, and plants.

Worm composting can also be compact and convenient. If you’re doing it right, the bin won’t stink and the worms won’t escape. Seasoned worm bin keepers know the view of a worm bin being a stinky, slimy, writhing mess is totally a myth!

Setting Up a Successful Worm Bin

Like anything else, there are plenty of ways to do a worm bin wrong. But if you follow these guidelines, you should be on your way to a successful first worm bin.

Get some worms.

These are NOT just any garden worms – they’re red wrigglers, or Eisenia fetida. No, you shouldn’t go dig worms from your garden to put in your bin, because they’re not the same. You can buy red wrigglers online or at some local gardening stores.

Get or make a bin for them.

You can buy specialty worm bins, or you can make your own. If you’re DIY-ing it, I’d suggest a plastic 5 gallon bucket for a smaller bin or a large rectangular tote for a large one. Make sure you have a lid, too, to keep out unwanted bugs and light. For your DIY bin, use a ¼” drill bit to drill rows of holes around the bottom of the bin, the middle, the top, and in the lid. The holes can be 4-6” apart. Don’t worry, if your bin conditions are right, the worms won’t want to crawl out – and worms need to breathe!

A super simple worm bin made from a 5 gallon bucket

Set up their habitat.

Just like any other pet, once you have the pet and its enclosure, you want to create the conditions for it to be happy and comfortable. So how do you make a plastic bin into a 5-star worm hotel? They need 4 things to start:

Some soil and leaves from outside. Just add a couple handfuls to a small shovel full in the bottom of your bin to give them a place to cover up until they start producing compost. If the dirt is very dry, spray or sprinkle it with water. It shouldn’t be soggy.
A little food to start out. It’s important not to overfeed them, because excess food attracts pests. My worms seem to like soft things like apple cores, banana peels, and slimy greens best.
Bedding. Once you have your worms nestled in with a little soil and a little food, cover them up with either some corrugated cardboard or shredded newspaper. This gives them a place to hide and helps regulate moisture in the bin.
A temperature range between roughly 45 and 90 degrees Fahrenheit. Don’t leave them out in a freeze or put their bin in direct sunlight! Think of them as pets that you don’t want to freeze or bake to death.

Feeding and Maintenance of your Worm Bin

Like I said before, you may want to start your worms on softer fruits and veggies. They’ll also eat harder ones like raw potatoes and carrots, but it may take them longer to break those down. The amount you feed them is important, but takes some trial and error. Give them a small handful of scraps, hiding it under the bedding. If it’s gone within a few days to a week, just give them more. If it’s still there after a week, you probably need to cut back or you’ll end up with that slimy, stinky bin full of fruit flies or other things you didn’t want in there. Keep in mind that your population will grow under good conditions, so you may have to increase the amount you feed them.

As they get bigger and more plentiful, they’ll be able to handle most food scraps – fruits and veggies, grains, even meat and dairy. The things you may want to stay away from altogether are alliums (garlic and onions), acids (coffee and citrus), and hot peppers. I’ve had friends with well established worm bins tell me their worms can handle anything, even these categories.

Continue to add bedding to the bin so there’s always some bedding on top. An excessively wet bin may need less food, or may need more bedding. The common rule of thumb is that the compost and bedding should feel damp like a wrung-out sponge, no drier or wetter.

Worm bin bedding – and some squash seeds sprouting.

Harvesting Your Worm Bin

There are different ways to do this, but sooner or later you’ll want to use some of that beautiful compost! The simplest method to separate your worms from their castings is to get a large tarp or sheet and dump the whole bin out in the center. Sort through it, handful by handful, separating worms from compost. When you’re done, put your worms back in their bin, give them a little bit of castings and some food and bedding, then go give your plants that delicious plant food. They’ll thank you for it!