The Stars of the Show
Compost Worms
Everything you need to know about selecting, feeding, and housing your composting worms.
Red Wigglers — What Type of Worm Is That?
Red Wigglers, Red Worms, European Red Wigglers, and Blue Worms are common names for several red-coloured composting worms. In Canada there can be 1 of 5 different species — all surface-dwelling compost worms. Each variety has unique features and benefits, and all like to co-inhabit, which is why it's often hard to find a single species on its own.
Earthworms are different. They are not surface dwellers and prefer making long tunnels in the garden. They're usually not found in high-organics environments. Earthworms are roughly twice the size of the red wiggler varieties, but both are great composters.
How Much Do I Need?
Worms are usually sold by the pound, and the amount you need depends on how much organic material you plan to compost. Try saving your organics for a week to gauge the volume. Compost worms can consume about half their body weight per day — for about 2 lbs of organics, you'll need about 1 lb of worms.
What Should They Eat?
Favourite Foods
- Most fruits — watermelon, apples, kiwi, grapes
- Most vegetables — carrots, broccoli, potato peelings
- Coffee grounds, including the filters
- Tea, both loose and in compostable tea bags
Do Not Feed
Worms are vegetarians. Avoid:
- Dairy products
- Meat, cooked or raw
- Oils and fats — dressed salad leftovers cannot go to the worms
- Citrus — very limited amounts only; citrus can make the bin acidic and the oils are harsh on worm skin
- Spicy onions and hot peppers — the hot oils can burn the worms' skin
What Is a Worm Bin?
The worm bin is where you'll keep your compost worms. Bins can be made from many different materials in endless shapes and sizes. You can construct one to fit a perfect space, or find a new use for an old dresser drawer. There are just a few requirements:
- It must be able to keep the bedding moist.
- Made from material that won't leach harmful toxins into the bin (avoid treated wood).
- Should have about one square foot of surface space per pound of worms.
Worm Bin Types
There are two types of worm bins: a box system and a flow through system. Box systems require more hands-on involvement to harvest castings but can be constructed with simple tools and materials. Flow through systems are stacked bins that allow worms to move upward to follow the organics, leaving castings behind — requiring much less effort to harvest.
What Can You Build a Bin With?
Most bins are built with wood or plastic and can be constructed to fit a specific space, upcycled, or purchased. Both have their advantages.
Wood Advantages
- Most versatile — can be built to fit any location, like a window bench or under the kitchen sink.
- New wood, recycled wood, or an old wine crate all work, as long as there are no toxin-leaching treatments.
- Paint the outside — make it a piece of art — but your worms prefer plain natural wood on the inside.
- Wooden bins breathe, so they require fewer air holes and excess moisture is absorbed by the wood.