Let’s face it, composting for kids comes down to taking smelly food scraps out to the back garden where you put it in a bigger pile of smelly food scraps, probably swarming with flies. Not exactly something they’re likely to tell their friends about at school.
However, add into the mix thousands of wriggling writhing worms and suddenly you have something news-worthy for the playground.
Worm composting is a great family project and an easy way to get kids excited about composting. Suddenly it’s not about composting, it’s about feeding worms!
Done well, vermiculture can offer a fantastic learning opportunity for your children as well as help turn kitchen scraps into fantastic worm compost that is invaluable in the garden or as a topping for houseplants. You’ll never need to buy organic fertilizer again!
The best thing is that you don’t even need a garden to do this as vermiculture can be done indoors and all year round. This is how you can get started with a worm farm…
Turning your kids into composting worm wranglers
Involve the kids with each step as there are different lessons to be learned along the way.
1. Calculate out how big a farm you will need. Start by measuring how much compostable material your household produces in a week. Collect only the materials that will go into the worm farm, which includes any vegetables, fruits and egg shells, but not dairy products, meat, oily things or bread products. The kids might be surprised at how much is produced and you can talk about where all of that would go if it wasn’t composted (i.e. landfills). A rule of thumb is that you will need one square foot of surface area per pound of kitchen waste produced per week. This is a nice little math problem for the kids.
2. Figure out what type of container will work best for you. The container you choose should be between eight and twelve inches deep and have the surface area that you calculated in the previous step. Other than that, it’s a matter of choice. Is it going to go on or under the kitchen counter? Or maybe in a shed, garage or on a balcony? Do you want to be able to access the composted material frequently for your garden, in which case a multi-tray system might be best. Can you source recycled materials like an old plastic tote or an old set of dresser drawers?
You can obviously get worm composters ready built, but they can be quite expensive. Here’s a cheap way to build a multi-tray worm composter using recycled polystyrene containers.
There are table-top worm farm kits available too, which might seem like a great idea for the kids, but the reality is they are too small for a composting system, they aren’t designed for the right worms, and composting worms are light sensitive so clear glass sides, though great for viewing, aren’t great for the worm.
3. Calculate the number of worms you need. This is another great little math problem for the kids. For every pound of compost waste per day use two pounds of worms (about 2,000). You can buy your worms from most gardening and hardware stores but you can also buy them online. The two species used are Eisenia foetida (commonly called red wrigglers, brandling or manure worms) and Lumbricus rubellus. If you can’t get the quantity your calculation requires, then just reduce the amount of compost you put into the worm farm until they start to multiply.
4. Make your worm bed. Once you’ve got your container, you’ll need to make a nice bedding layer for the worms. This can be made of shredded newspaper, cardboard or leaves. Chopped up straw, composted manure, and sawdust are also great additives. Also add some sand or soil as this provides some necessary grit for worm digestion (I’m sure there’s another lesson for kids in there somewhere). The bedding should be moist and fill about ¾ of the container. Here’s a bit more information about making a worm bed:
5. Add your kitchen scraps. Once your worms are snug in their bed, it’s time to start adding your kitchen scraps. As I mentioned before, vegetable and fruit scraps are best. The kids will love doing this. Have a small shovel or spoon to dig a hole to add the kitchen scraps, add the scraps into the hole and then cover them up. You’ll want to add once a week to a different area of the bin. You can use a marker, such as a popsicle stick, to ensure you are adding to a different spot each time.
6. Maintain your farm. If you’re using a single bin style farm, you can simply remove composted materials gradually and add new bedding in as you remove material. Otherwise, you can dump the entire bin out onto a plastic sheet and separate the worms out by hand. I guarantee the kids will enjoy the latter method more. It will give them a good chance to see how the farm is doing. You can help them figure out whether there are more or less worms than you started with and discuss why that might be. If there are less, it’s a good opportunity to sort out what might be wrong. Perhaps it’s too moist, in which case more drainage holes are required.
You might find that when you open the lid of your worm farm that there are a lot of worms on the sides or lid of the bin. This is a good indicator that they aren’t happy in the soil, so you’ll have to sort out what’s going on, whether it’s moisture or maybe a population explosion.
Another indicator that things have gone awry is if the farm starts to smell. This is usually a sign that things are too moist. To help with this, you can add more drainage holes, but also be sure the farm is up on blocks to allow air to circulate underneath. A tray should be put underneath to collect the moisture that drips out…gardeners call this liquid gold as it can be diluted and used as fertilizer.
7. Put your product to good use. The worm compost is great for the garden or house plants. Get the kids involved with putting the worm poop to good use so they can see the benefits of their efforts.
Other lessons learned for kids:
Besides the obvious lesson of reducing our waste in landfills, there are a number of other lessons that worm composting can teach kids.
Maths – It’s always more fun to do calculations if you can see a purpose to them. Those few calculations for determining the size of the farm and the number of worms you need are a great way to make maths fun for kids.
Ecology – The process of decomposition is fundamental to ecology and the children are witnessing it first hand with their worm farm. They can then apply this to what happens to leaves and debris on the forest floor. You can talk about what other organisms are at work in a forest compared with the worm farm (fungus, bacteria, insects).
Worm biology – There are a number of opportunities here for some basic worm biology lessons. Take one of the worms out of your compost bin and find a worm from your garden. Put them in separate dishes to compare the external anatomy – the kids can even draw them or take photographs to help make comparisons.
Observant kids may start to notice that certain food scraps are always eaten last by the worms, suggesting they have food preferences. For instance, they generally don’t like citrus peels or onions. With this in mind, you can help them design an experiment to test worm food preferences. Place a worm on a moist paper towel. Dip absorbent paper (such as litmus) in a number of different substances (try vinegar, lemon juice, carrot juice etc). Place the strips one at a time near the worm and watch its behaviour. Does it seem repelled by the smell or attracted to it?
Business – If you get a great farm working well, the kids can even learn a little about business. Maybe they can build and sell worm composters to friends, complete with extra worms produced on their farm. Or perhaps it’s just as simple as selling seedlings grown with the worm compost at the end of the driveway…or even small bags of worm compost. It will differentiate them from all those lemonade stand kids!
Worms make composting for kids a lot of fun. They’ll be learning all sorts of lessons without even realizing it. It also sets a good example for how we should deal with our waste for the upcoming generation!