So You Want a Worm Bin

I recently wrote a post detailing my adventures with a worm bin. Here are some questions I maybe could have asked myself before I leapt straight in. (Read about my worm bin adventures here.)

What is a worm bin?

A worm bin, also called a worm farm, is a container that houses worms. The worms used in worm composting are not not earthworms; they prefer leaf litter and vegetables to dirt. An established worm bin can break down your food waste in anything from a few days to a week. This process, called vermicomposting or worm composting, produces fertile worm castings that are are rich in nutrients. You can add them to your garden soil as a fertilizer, or you can use them to mix your own soil when you are getting a garden going.

A worm bin can be any container large enough to hold your worms, whatever you’re feeding them, and the resulting compost. Most worm bins you can buy are plastic containers with two or three trays and a lid. They are usually elevated and have a spigot on the bottom to let out excess liquid. My worm bin leaked a little bit, so I put a plastic container underneath to catch any drips. It also makes it easy to drain the reservoir when needed.

If you prefer liquid fertilizer, worm tea is great for your plants. After I had watered half of my garden with the excess liquid from my worm bin, I found out this liquid is actually “worm leachate,” not worm tea, and it’s not beneficial at all.

Why wouldn’t I just make a compost pile?

There are several advantages to worm composting over maintaining a standard compost pile. For one thing, worms break down your vegetable remains a lot faster than microbes alone. That means a compost pile is going to get large quickly, while you’ll be able to empty the trays of your worm bin more often. Using a compost pile is called “hot composting” because the inside of the pile can get hot enough to kill beneficial microbes (and worms). The pile must be constantly turned to aerate it. Worms do the work of aerating your compost for you as they burrow and move around.

However, worms are more sensitive to heat and cold then a compost pile, and they are pickier eaters. If you live in a particularly cold or hot climate, you may need to do a bit of research about whether worms will survive outside, or whether you would need to keep your worm bin indoors. Worm bins tend to be compact and not very smelly, so they can live indoors if needed. My worm bin is outdoors for now, but I will probably need to bring it indoors during our first summer heat wave.

Order local

Before you spend hours comparing worm bins, check if your city or county gives any discounts or support to aspiring worm composters. When I told a friend that I had just ordered a worm bin, she said: “That’s awesome! I have two. Isn’t it great that San Jose gives you a discount on worm bins if you’re a resident?”

“…They do WHAT?” I said.

Something to think about before you invest in a warm farm.

DIY or no?

I initially considered following a do-it-yourself guide to make my own worm bin out of a plastic storage bin, until I got to the step that required drilling a bunch of holes using large drill bit, and then potentially doing this several times to make multiple trays. If you don’t make your DIY worm bin with multiple layers, it’s harder to sort out the worms from the dirt when you get to the point of “harvesting” your compost. But if you have the interest and the time, it’s certainly a cheaper option.

What comes first: The worms or the worm bin?

My worm bin came with everything I needed to get my worms going, but it did not include any worms. Thankfully, I checked that on the website several times. And I was very glad that the worm farm I ordered from ships the worms in the same shipment as the worm bin, because it would have been very exciting if I had 250 worms on my hands without anywhere to put them.

Be honest with yourself: How much worm food do you generate in a week?

I went with a small worm bin because I am one person and therefore, I assumed, do not generate very much warm food, even though I knew perfectly well that my compost fills up every two weeks if I’m lucky. I have a banana with my breakfast every day. Banana peels take up a lot of space. I also went with a small order or worms (and I suspect quite a lot of them died or were, erm, eaten). Established worms can eat their weight in a few days. It turns out 1000 worms weigh about a pound. My quarter pound (or less) of worms are struggling to keep up.

So, things haven’t been disintegrating quite as quickly as I’d hoped. I suspect this will not be as much of an issue once the weather warms up and the worms have a chance to multiply.

Do your research

Things have improved now that I’ve researched feeding my worms a bit more. I spent fifteen minutes the other day chopping up partially decomposed banana peels into worm-sized pieces. So, you know: Do your research.

Do you have a use for all the dirt you’re going to be generating?

This is one I’m not sure I can answer in the affirmative. But since I have a friend with a garden, I figure someone can use the dirt even if I can’t. (Who am I kidding? At the rate my spider plants are multiplying, I’ll have plenty of use for it. And my veggie garden is in full swing; more on that in another post.)

Do you like worms?

This isn’t required. I’m just asking. They’re pretty cute if you give them a chance.

Are you willing to be patient?

Worms break down your food much faster than a standard compost pile, but it does still take time. If you feed them too much too fast, you will be like me, cutting up partially disintegrated banana peels and mixing them back into your worm bin on a Wednesday night when it starts to smell. (Yuck.)

On the bright side, if you forget about your worms for a while, that is probably to your benefit. They won’t mind, and a watched worm bin…well, it still composts, but slowly.

So you want a worm bin

My advice is: have at it. It’s a fun project if you’re looking for a way to use compost, especially if you have a garden that could use some fresh worm castings.

What I’m Reading

Support your local bookstores! Here are a couple good worm-related books from mine:

The Earth Moved by Amy Stewart

I read this book when I was in elementary school around the time my dad got his first worm bin. (This may tell you something about what kind of child I was.) I have very fond memories of it, and it was the first nonfiction book I enjoyed. It covers different kinds of worms, how worms behave in the wild, and the important role they play in soil development.

After I ordered my worm bin, I picked up my copy of this book and flipped through it, looking for tips on worm composting. No luck. I had forgotten that the author leaves that sort of thing for other books to cover. However, it is a great read if you think of worms as friends.

Worms Eat My Garbage by Joanne Olszewski and Mary Arlene Appelhof

The author of The Earth Moved recommends checking out this book if you’re thinking of worm composting. I haven’t read it, but I hear it’s a good book to read before you buy 250 worms online.