How To: Start a Worm Compost
A worm compost is a fun, easy way to get a classroom full of kids excited about composting. There’s nothing quite like burying your lunch leftovers and then coming back a week later to find them broken down and almost unrecognizable (and of course, crawling with worms!)
Items you will need:
- A large Rubbermaid container with a lid
- A large tray that will fit under the container
- A bucket full of water
- A handful of sand
- Red Wriggler Worms*
- A drill
*Red Wigglers are the best for composting because they thrive on organic materials.
Steps to setting up a worm compost:
- Give your Rubbermaid a quick rinse with some water.
- Drill 8 to 10 holes in the bottom of the Rubbermaid bin for drainage.
- Shred your newspaper into strips that are roughly an inch wide.
- Soak the newspaper in the bucket full of water.
- Take out handfuls of the newspaper and squeeze out the excess water. Fluff the newspaper out again and put it in your Rubbermaid bin.
- Fill the Rubbermaid container to the halfway point with damp newspaper.
- Throw in a handful of sand. This will provide the grit the worms need to digest the compost.
- Place your worms in the bin.
- Place your compost in a corner of your bin, a couple inches under the bedding.*
- Place the lid of the bin under the container (to catch any water that drains out).
*People sometimes worry that their worm compost will smell, but when put together properly, there is little to no odor. To prevent odor, it is important not to overfeed the worms. Start with a small handful of compost. You should check on your worms weekly, so during your next check, see how much they have eaten. If the compost is totally gone, add a bit more next time. If there is still a lot left, put a little bit less in next time.
Harvesting your compost:
After a few months, the original newpaper bedding will be gone, and your bin contents will be brown and earthy. This means it is time to remove some of the finished compost!
Get a large plastic sheet, and dump your worm compost onto it. Have your students sort through the soil and pick out the worms and any tiny, lemon-shaped spheres. These are worm cocoons that contain up to 20 baby worms! The worm-free soil can be used in your gardens, and you can refill your worm bin with fresh bedding before putting the worms and eggs back.
- Worms prefer cool, dark places. Don’t put your worm compost right beside the heater!
- Worms enjoy fruit/vegatable scraps, coffee grounds, tea bags, and crushed eggshells. They cannot eat meat or dairy. Try not to include more than one orange peel at a time either.
- Put the compost in a different corner of the bin each week. This will encourage your worms moving around the bin.
- If your bin in looking dry, assign students to spray with a mist bottle as needed.
Need some inspiration on how to get your worm compost started? Check out the work done by Robson StrongStart Centre, James Gimore Elementary, or Cloverdale Catholic School.