What is a worm compost bin and how to make one for your garden [with photos]

Our Oakland preschool recently installed a wiggly worm compost bin thanks to one of our amazing parents! We thought this was the perfect opportunity to share why we’re doing it and how you can make one for your own garden. 

Why?

It’s not only great for creating high quality compost and soil for the garden, it’s an exciting long-term science experiment for preschoolers as they monitor progress and learn how to recycle, and how nature recycles [puts on Circle of Life music].

How to make a worm compost bin

1. Obtain a worm bin

This is basically a home for all those amazing worms and the place they digest all the delicious organics you give them. You can find them online, at your local DIY store or garden center.

• Good ventilation
• Cover (to stop light getting in)
• A good size (the bigger the container the more worms you can have)

2. Find the perfect place

   Be sure to place your worm bin in a cool area to protect it from excessive heat like in shade, under a tree, along the side of your home. Try to keep the temperature in the bin between 30 and 70 degrees Fahrenheit. This will make the perfect home for your compost-crunching worms.

3. Prepare the bedding

The trick here is to create the natural habitat of places where you would normally find a worm. It’s a good idea to start off with dry grass or if you don’t have that, shredded newspaper, unbleached corrugated cardboard, sawdust, or straw will do.

Teaching point: This provides a source of fiber to our wiggly friends and keeps your worm bin airy.

Next, sprinkle some dirt on top and then water until the whole bedding is nice and moist. Let the worm bed soak for at least one day before adding the worms.

Warning: Avoid putting leaves in your bedding as some act as an insecticide and will kill off the worms

4. Find some worms!

Try to avoid plucking them from your garden. Instead, search online, visit a garden center or speak to your local gardening club to find about one pound of worms.

5. Dinner time

Be sure to feed your worms digestible amounts regularly. They can eat the same fruit and vegetables as you and I as well as tea leaves, egg shells, bread, and grains. However, try and leave out citrus fruit and don’t feed them too much as when the food decomposes the heat will kill off the worms.

When you drop the food into the bin, try and mix it in with the bedding. This will keep the fruit flies at bay and also means the worms can eat through it quicker.

The worm bedding should have the dampness of a wrung out sponge so you may want to sprinkle a little water when you add food to your worm compost bin. If it’s too wet the worms will try and get away, believe me they can wiggle out of anywhere they don’t like.

Top tip: if you want to speed up composting make sure your food is in smaller chunks.

6. Harvesting

After 3-6 months you should have quite a lot of compost and your worms will have multiplied! When you’re ready, try and separate the worms and compost into two piles but bear in mind you won’t be able to save them all.

Don’t forget

When you’re ready to harvest the compost, you’ll need to make new bedding for the worms.

Read more: 3 easy science projects for preschoolers