Outdoor composting is a fantastic way to create nutrient-rich soil while reducing household waste. But did you know you can take your composting game to the next level by adding compost worms? These hardworking creatures—often referred to as nature’s recyclers—can speed up the decomposition process and produce higher-quality compost. If you’re in Ontario, Canada, this guide will help you make the most of your outdoor compost pile using compost worms.

Why Add Compost Worms?
Adding compost worms, such as red wigglers (Eisenia fetida), to your outdoor compost pile brings several benefits, including:
- Faster Composting: Worms break down organic matter more quickly than traditional composting methods, reducing the time needed to produce nutrient-rich soil.
- Higher Nutrient Content: Worm castings (a fancy name for worm poop!) are rich in nutrients and beneficial microorganisms that can enhance plant growth and soil function.
Considerations for Worm Composting in Ontario’s Climate
Ontario’s climate can be challenging, especially during colder months. Here are some tips to keep your compost worms healthy and happy year-round:
- Temperature Management: Worms thrive between 55°F and 77°F (13°C to 25°C). During winter, insulate your compost pile with straw, leaves, or cardboard to retain heat. Positioning your pile against a wall or fence can also help protect it from freezing temperatures.
- Moisture is Key: The compost pile should have the consistency of a wrung-out sponge—moist but not waterlogged. Add water during dry spells or use moist bedding materials like shredded cardboard or leaves if needed.
- Shade and Ventilation: If your pile is in direct sunlight during the summer, cover it or move it to a shaded spot to prevent overheating, which can harm your worms.
Step-by-Step Process for Adding Worms to Your Outdoor Compost
1. Choose the Right Worms
Red wigglers (Eisenia fetida) are ideal for outdoor composting because they thrive in high-organic-matter environments and are efficient at breaking down waste. Avoid using regular earthworms or nightcrawlers, as they don’t process organic material as effectively.
2. Prepare Your Compost Pile
Before adding worms, make sure your compost pile is active and has plenty of organic material like fruit and vegetable scraps, coffee grounds, and yard waste. Avoid adding meat, dairy, or overly acidic foods like citrus peels, as these can harm the worms.
3. Create a Worm-Friendly Habitat
Add a layer of moist bedding material, such as shredded newspaper or cardboard on top of your compost pile. This will provide a comfortable environment for the worms to burrow into and help regulate moisture levels.
4. Add the Worms
Introduce ½ to 1 pound of red wiggler worms per square foot of compost pile area. Gently place them on top of the bedding layer, and they will naturally burrow down into the pile to find food and moisture. If you’re adding a cooler time of year, feel free to put them closer to the middle of your pile.
5. Maintain Your Pile
Keep the compost pile moist and feed the worms regularly with kitchen scraps. Avoid letting the pile dry out or become too compacted, as worms need moisture and airflow to survive. Aerate the pile occasionally to ensure adequate oxygen circulation.
6. Protect During the Winter
When temperatures drop, insulate your compost pile with straw or leaves to retain heat. Alternatively, harvest some worms and set up an indoor bin for the colder months, then reintroduce them to the pile in spring.
Wrapping Up
Adding compost worms to your outdoor compost pile in Ontario is a simple yet effective way to produce high-quality compost faster. With proper care, your worms will not only thrive but also transform your compost pile into a rich source of nutrients for your garden.
If you’re excited to try vermicomposting and want more tips, why not start today? Grab some red wigglers, set up your pile, and watch the magic unfold. Your garden—and the environment—will thank you!