Homemade Worm Composter (for a Few Bucks)

Worm compost or vermicompost is the product of decomposition in the worm digestive system. Yes, it is worm poop. And it's really good for plants because it's rich in many nutrients.

How does it work?

In short, you give your worms vegetable leftovers, they process it and create the compost.

How does it help keep the Earth green?

Worm compost is a perfect fertilizer and thanks to the rich nutrient content, it's pretty universal - I use it for tomatoes as well as orange trees and decorative plants. It's not just the compost though, the secondary product called worm tea is also great for fertilizing. Therefore, you get rid of vegetable leftovers in a sustainable way and you get an ecological fertilizer. No need to drive to the shop, no need to get it shipped.

And one HUGE advantage! The worm compost doesn't smell, so you can keep the composter in your kitchen!

How much does it cost?

Worm composters are in fashion right now and they are sometimes much more expensive that they need to be. Several years ago, I decided to make a few vermicomposters for our little farm and I didn't want to spend much money on it. In the end, I made 4 smaller composters that cost me around 40 USD but it's because I wanted to get them close and fast rather than cheaper and having to wait. As for the worms, I would recommend you to look not just at e-shops but also individuals who sell them. Where I live, I can get around 200 worms (good for small kitchen composter) for around the equivalent of 4 USD.

Do you like sustainable projects? Check out Recycle & Upcycle!

For one composter, you need:

1. 2 plastic buckets
2. 1 lid
3. drilling machine with a drill of approx. 0.4 in (don't worry if it's larger or smaller, you just don't want the holes to bee extremely large)
4. worms - red wigglers
5. 2 handfuls of earth
6. optional: shredded egg carton, coconut shell shreds
7. optional: yoghurt cup, piece of wood...I'll explain later

The buckets can be of any size you like but both should be the same size. I recommend getting buckets that get thinner towards the bottom OR that have a rim. The point is that you have to put one bucket inside the other and there needs to be space left between their bottoms. If your buckets don't fulfill any of these requirements, I'll show you a solution later.

The lid must fit the bucket.

Drill holes in the bottom of ONE of the buckets. I like to drill them in a regular fashion but you can drill them randomly, just make sure there isn't a large space without a hole. (pictures 1 and 2)

Drill holes just under the rim of the same bucket, all around the circumference of the bucket. (picture 3)

Drill holes in the lid. (picture 4)

Place the bucket with the holes inside the bucket without holes. Cover with a lid. The bucket is ready to be filled. (picture 5)

If your buckets are touching at the bottom and there's no space left, place an upside down plastic yoghurt cup or a piece of wood in the center of the lower bucket. This space is absolutely necessary, that is where the excess liquid will go. (picture 6)

When I started with this type of composting, I was told there should be a layer that soaks in the excess liquid at the bottom of the upper bucket. I ended up not liking this and not needing it because I don't deal with excessively humid worm compost. However, keep this in mind in case you live in a more humid place, then this might come handy. (picture 1)

If you didn't get worms with earth, put a little earth at the bottom of the upper bucket. (picture 2)

Place the worms on the earth. (picture 3)

Give them something to eat (see next step) and stir the food in a little. (picture 4)

New worms take several weeks to settle in and start producing properly, so don't worry if you don't see much happening at the beginning. After some time, things will go really fast and you might even feel like you don't feed them fast enough.

There have been enough blogs and books written about how to feed the worms and keep them well and alive so I won't go into details but I'll share a few basics. First of all, even if you see a 200-page book of worm composting, don't let it scare you off, it's pretty easy.

This is what works for me:

I give the worms only vegetables, fruit tends to catch mold. If I want to give them fruit leftovers, I give them only a very small amount and mix it in the earth properly. But as for the present, I avoid fruit completely, it's easier than checking for mold and I use the fruit for another type of compost. I cut the vegetables in small pieces, this way, they process it faster. I do this especially with vegetables with higher sugar content like red pepper that is more prone to catching mold.

I find green vegetable parts are the best but just figure out what works for you, also different varieties of the same vegetable may work differently (the worms might like one more than another).

About once every two months, I mix a spoonful of worm minerals in the earth.

I watch the humidity of the compost. If it's too wet, it means the liquid isn't draining well and the worms literally drown. If it's too dry, the worms die as well. The ideal humidity is slightly damp, so you can form a ball in your hand but it's not muddy. If the compost is too wet, put some shredded egg cardboard in the compost and consider making more holes in the bottom of the upper bucket. Also, check if the bottom bucket is full of liquid and the upper bucket stands with its bottom in this liquid.

If the compost is too dry, pour or spray just a little clean water on the compost and stir it in. At least in my case, if I don't stir in the water, the compost catches mold.

Worms prefer temperatures 53-77°F/12 - 25°C. I never keep them at lower temperatures but I quite usually have them at 95°F/35°C in summer and they are always just fine.

After a while, you'll see that the veggie leftovers are disappearing and there's more of what looks like black earth, this is the compost. (picture 1)

A compost ready to harvest has no leftovers or very little and you might even notice small round pieces resembling coffee beans. (picture 2)

To harvest worm tea, simply remove the upper bucket and use the liquid in the lower bucket. It's strong and it might burn some plants, so better mix it in water. I use the ratio 1:2 (1 part of worm tea in 2 parts of water).

To harvest compost, I use one of these two ways:

1. Fast way: If I need compost fast, I use the fact that worms are sensitive to light. I extend the compost over a plastic sheet in a layer that is about 2 inches thick. The worms escape to the bottom to avoid light and I harvest the top layer. Then I return the worms to the bucket.
2. Slow way: This takes around two weeks (or more) but if I have the time, I do it this way because it's let work, less moving of the compost. I start feeding the worms just in one spot in the bucket. Slowly, they move to this spot and in a few weeks, I harvest all the compost but this spot and a little around to avoid grabbing worms.

If you get to the point where your bucket is getting full because you probably haven't harvested the compost for a long time, you basically do what I described in the previous step as the slow way. You will need another bucket with holes in its bottom. You place this new bucket in the bucket with the compost (so now you have stacked 3 buckets), you place some compost at the bottom and start putting the food there. The worms will move in the new bucket through the holes. This only works when there's no food left in the full bucket.