Composting with worms is a great introduction to composting that’s easy to do with limited space and resources. You don’t need to build a huge pile in your backyard or have a large amount of waste to compost. Worm farms can even be kept indoors. Many people get started with their first worm farm using a simple storage container. There are many worm composting systems you can buy, but you can easily build one with just a few supplies. Kids really get a kick out of playing with worms and it’s a great hands-on project to introduce them to composting.
Supplies Needed
- 2 large plastic totes – length is more important that depth. 5-10 gallons is good for a classroom or homeschool project. The totes in these pictures are 18 gallons which is a good size for a larger farm for beginners.
- 5 gallon bucket
- drill with a small bit (1/8″ bit)
- small compressed brick of coconut coir
- shredded black and white newspaper, shredded paper grocery bags or shredded cardboard
- handful or two of dirt from your garden, used for grit and doesn’t have to be great quality, just regular ol’ dirt.
- a brick or a few rocks
- 1/2 – 1 lbs of red wiggler worms – This is the easiest worm for beginners. These aren’t the worms from your garden. Many local nurseries carry them in the spring.They can also be found sold as fishing bait or you can get them from link. There is a company that sells on Amazon but there have been many complaints about quality. I wouldn’t buy them from Amazon.
- if you live in a humid climate – box cutter, small piece (2′ x 2′ max) of window screen, duct tape
Supplies for Worm Bin
Step 1 – Drill holes in one tote
This is the only part of the project that may not be appropriate for kids to do themselves, but it can be an easy introduction to power tools and safety. Please supervise them closely if you have them drill the holes.
One tote will rest inside the other one. The bottom tote will act as a basin to catch any water leaching out of the worm farm, but there shouldn’t be much water. Put a brick, or a large rock or two, in the bottom tote. The other tote will rest on top of the brick. It only needs to rest an inch or two above the top of the base tote. On the bottom of this top tote, drill several 1/8″ holes to allow excess water to drain into the bottom tote. Drill 1/8″ holes, spaced about 2″ apart, all around the top of the top tote. These holes will help with ventilation and need to be above the top of the base tote.
How many holes you drill in the lid will depend on where you live. If you live in a humid climate, you’ll need to remove a large section of lid and cover it with window screen and secure it with tape. For those of us in a dry climate, that much ventilation will make the worm farm dry out very quickly. We only need to drill holes in the lid. If you cut a small window in the lid and cover it with window screen, start with a small area just in case you lose too much moisture. You can always make the window larger if needed. If you find worms climbing up the sides of the bin, then you need more ventilation.
Left – drainage holes drilled in bottom, Right – mixed bedding in bin
Step 2 – Prepare Worm Farm Bedding
Bedding in a worm farm is extremely import to balance the nitrogen materials. Always err on the side of too much bedding. Start with about 2″ of bedding in the top tote. (You will also be adding more bedding every time you feed the worms).
I use a mix of coconut coir, shredded black and white newspaper, and paper grocery bags. You can shred the newspaper and paper bags with a regular paper shredder or by hand. Just tear it into small strips. Shredded cardboard also works, but that takes a much larger paper shredder than most people have at home. If you want to shred cardboard by hand, soak it in water first to make it easier to tear.
Please don’t substitute peat moss instead of the coconut coir. Peat moss isn’t sustainable and it has anti-microbial properties which is not what you want in any gardening activity. We want to encourage beneficial microbes. Coconut coir is easy to find online if you can’t find it locally. I prefer to use the small compressed bricks for worm farms because we don’t need huge quantities of it.
Soak the compressed coconut coir brick in a 5 gallon bucket with a bit of water to expand it. Gradually add more water as needed. Fluff it up with a handheld garden fork or a trowel. Mix in about an equal amount of shredded newspaper (and/or shredded paper bags, cardboard). You want the coir and newspaper to be damp like a wrung out sponge. When you squeeze a handful of it, only a few drops of water should fall.
Mix in a few handfuls of dirt. They need this for their gizzards. You can also add pumice.
Once everything is thoroughly mixed, add it to the top tote. Mix in more shredded newspaper if needed to reach a depth of about 2″.
Red Wiggler Worms from my local nursery
Step 3 – Add the Worms
Add 1/2 to 1 lb of red wiggler worms to your worm farm. Smaller worm farms will be fine with just a 1/2 lb. If time is an issue, you can leave the worm farm sit with the bedding until you’re ready to add the worms. Don’t buy the worms until you have a farm ready for them. You want to make sure to buy Eisenia Fetida (red wigglers). There are other composting worms, but these are the easiest for beginners.
New worms like to explore and can sometimes escape, so leave the lid off the farm for a few days and place the farm under a light. This will force the worms to move down into the bedding and help them settle into their new home.
Step 4 – Find a Location for the Worm Farm
If you’ve set up the worm farm as a classroom project then just keep it in your classroom. If you want to keep it in your garage or basement, make sure to monitor the temperature. Red wiggler worms do best when their bedding and food area is between 55 and 75 degrees F. This area may be higher than room temperature if you’ve added a lot of nitrogen rich foods like leafy greens. Pay extra attention to temperature if you want to keep it outside. Keep it out of direct sunlight. You may have to move it to different places with different seasons, or bring it indoors during extreme heat or cold. If the farm’s temperature drops below 55 degrees F, the worms will slow down feeding and reproduction. Temperatures above 85 degrees F can kill the worms.
Now that your worm farm is built and stocked with worms, it’s time to learn how and what to feed them. It’s super easy, but there are a few rules you’ll want to follow. Check out the next post in this series for all the details.
Other Posts in this Series
Post #2 – How to Feed Composting Worms
Post #3 – How to Harvest Worm Compost
More Garden Fun with Kids
Gardening with Kids – Child Led Activities
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