DIY Vermicomposting I: Compost Year-Round with a Small Investment

Tis the season for gardening! I’ve written about my garden antics at GeekMom before, but much of the time I was living in Florida, I had numerous constraints. Between the unforgiving climate, the fact that I was living in a rental property and had to keep to container gardening, and my picky-eater household, it simply wasn’t quite as fun.

But now we’re in Colorado, and homeowners, and I’ve been dominating my ever-longer days with digging up part of my backyard to put in raised beds and get my seeds going.

I will be writing about some of the projects we’ve been up to with our new house and new garden, but I want to start with this project I did while we were living in Nebraska two Air Force tours ago: DIY vermicomposting. I will write three posts about vermicomposting: Starting an bin of your own, harvesting the worm castings, and looking for signs of reproducing worms.

For this first post in the series, I will present you with an inexpensive way to start a worm bin of your very own. This was the vermicomposting method I used from late 2009 through mid-2013. We’ll discuss the fate of those worms in a future post.

Constructing a Basic Worm Bin

In summer 2009 while I was working on my garden just after a 1/2-inch soaker, I noticed the plethora of earthworms surfacing—and how fabulous the soil is when lots of earthworms are working through it. The soil remains aerated and rich. The boys and I dug up a couple hundred worms and tossed them into the compost bin. There were enough yummies still in there for the worms to help things out some.

That, of course, led me to hopping on the web and learning more about the worm casting process. Fascinating! With little more than a plastic bin and the old bills and papers I shred anyway, I could continue to generate compost all year long, even when my outdoor compost bin has shut off for the winter. Perfect for my garden!

I ordered a batch of red wiggler worms. In the meantime, I started preparing a bin so that as soon as the worms arrived they could go in.

I found many commercially available household worm bins for sale, usually for $75 to $150. I pondered whether this was something I could do myself.

First, I found one of the many storage totes** that I tend to break out for military moving time. You’ll see that the one pictured below was marked “Christmas” and was filled with old Christmas lights from the previous year. Over the past couple years, we’d converted to LEDs, so I just tossed the old incandescent lights into a paper bag until I found a means to recycle or repurpose them. With a drill, I added some 1/4-inch holes into the bin, across the bottom and along the top half.

**Ensure whatever container you choose is opaque. The worms work best in dark conditions.

I then filled the bin with shredded paper and some paperboard, such paper egg carton material. Then, I wet down the paper to a “wrung-out-sponge” consistency. The worms now have a new home waiting for them.

Now, let’s get some worms!

Choosing the Worms

There are two types of worms popular among worm composters: red wigglers (or “red worms”) and African Nightcrawlers. The red wigglers are more commonly available and less expensive, while African Nightcrawlers cost more per worm, but are bigger and will eat much much more.

We have been using red wigglers; one pound is a perfect amount for our family’s needs.

I mail-ordered my worms in 2009, and the company I chose sent high-quality worms with very few (less than 10?) that didn’t make the journey. When the worms arrive, it’s easy to simply add them to the prepared bin, with some food scraps on one side of the bin.

For my most-recent batch of worms, I went with a local retailer. I just received them this week, and we didn’t waste any time putting them in the bin with some food.

Note that worms will not ship all year long.

Managing the Food

You can feed red wiggler worms the same kinds of scraps that you would send to your backyard compost bin. Fruit scraps, vegetable scraps, and even some bread scraps will work if they aren’t too high in fat. Worms will gravitate first towards older, more decayed food scraps, such as browned apples, bananas, and rotting produce scraps. If you visit with your worms every few days, you can get an idea of what kinds of foods your worms enjoy the most. For the worm bin I kept from 2009 to 2013, the worms’ favorite foods seemed to be banana peels and sweet pepper scraps. They didn’t care for citrus, to the point that they attempted a mass exodus.

The more rotten the food is, the more quickly the worms can process it. Keep an eye on any stagnant food; it might be a sign that it isn’t rotten enough.

How much food should be fed to the worms? I’ve read that a good rule of thumb is to provide approximately half of the weight of your worms per day to the bin. My family of four is good with 1 pound of worms, which requires about 3.5 pounds of food scraps per week. This is merely a rule of thumb, and you will get a gauge of whether you’re providing enough food or not based on the worms’ behavior. If the food seems to be processed quickly, feel free to add a little more. If the food is sitting stagnant, you might want to look at backing off some.

I had read guidance to keep the food scraps to one side of the bin, and allow the worms to focus their energy on one side. That way, you can harvest the castings by working the worms from one side of the bin to the other. But that’s for another post.

Maintaining Moisture

Worms need moisture. You can see evidence of this if you go out on a sidewalk on a warm day with a heavy rain followed by sunshine. You might see the dried worms all over the sidewalk, right?

In the interest of not drying out your worms, you will need to periodically check the bin to ensure the right levels of moisture are maintained. You want most of the material to be as moist as a wrung-out sponge. More than that will bring unwelcome bacteria and odors, which could be detrimental to your worms. I’ve found that the moisture levels self-regulate after a while, at least until harvest time. For the first couple months, I had to do the “squeeze test” to make sure the balance was correct.

The “squeeze test” is done by grabbing a handful of the worm materials and giving it a squeeze. If more than a couple drops can be wrung out, you need to add some dry bedding material, such as coir (coconut fiber) or shredded paper, to help absorb the excess moisture.

If the worm bin looks visibly dry or dry to the touch, spray the top with a mister bottle of water. You can also wet a couple sheets of newspaper and lay it on top of the bedding material.

Cost Breakdown

The worms will be the most expensive part of this process. Like I said above, you can invest in a higher-quality worm bin, but if you aren’t ready to take that leap, stick with a storage tub for now.

• Rubbermaid storage tote: $10-15
• One pound of red wiggler worms: $35-40

I’m not going to consider the shredded paper and food scraps as costs; I will assume you produce those things free of charge.

What Do the Kids Think?

Well, one of my sons was absolutely fascinated with it! He had no problem handling the worms and asked numerous questions.

My older son was more skittish, unfortunately.

Next up, a post about worm reproduction!

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