So you've decided to start a worm compost bin — congratulations! Vermicomposting is one of the most efficient, rewarding, and eco-friendly ways to recycle kitchen scraps into nutrient-rich fertilizer for your garden. But before you set up your bin and start tossing in banana peels, you need to answer one critical question:
Which worms should you use?
Not all worms are created equal when it comes to composting. You can't just dig up earthworms from your backyard and throw them in a bin. Composting requires specific species that are adapted to living in concentrated organic waste, eating decomposing material near the surface, and tolerating the confined environment of a worm bin.
At Wired Worm Farm, the two species we raise and recommend for vermicomposting are Red Wigglers (Eisenia fetida) and European Nightcrawlers (Eisenia hortensis). Both are excellent composting worms, but they have different strengths. Let's compare them so you can make the best choice for your setup.
Red Wigglers (Eisenia fetida): The Gold Standard of Composting Worms
If you've done even a little research into vermicomposting, you've probably already encountered Red Wigglers. They are, by far, the most popular composting worm in the world, and for very good reasons.
Why Red Wigglers Are Great for Composting
1. They're voracious eaters.
Red Wigglers can consume approximately half their body weight in food every single day. A pound of Red Wigglers (roughly 800–1,000 worms) can process about half a pound of kitchen scraps daily. That's a significant amount of food waste diverted from landfills.
2. They reproduce quickly.
Under optimal conditions, Red Wigglers can double their population every 60 to 90 days. Each mature worm can produce 2–3 cocoons per week, and each cocoon can hatch 2–5 baby worms. This means your bin's processing capacity grows over time without you needing to buy more worms.
3. They're surface dwellers.
Red Wigglers are epigeic worms, meaning they naturally live at or near the soil surface in decaying organic matter. This makes them perfectly suited for the shallow, layered environment of a worm composting bin. They won't try to burrow deep underground — they're happy working through your food scraps and bedding right where you put them.
4. They tolerate crowding.
Unlike many earthworm species, Red Wigglers don't mind living in close quarters with lots of other worms. High population density doesn't stress them out the way it would stress a deep-burrowing species.
5. They produce excellent castings.
Red Wiggler worm castings are prized by gardeners for their nutrient density, microbial diversity, and soil-building properties. The castings produced by Red Wigglers are some of the finest vermicompost you can get.
Red Wiggler Considerations
- They are smaller than Nightcrawlers, typically 3–4 inches when fully grown.
- They are not the best choice for fishing bait due to their small size (though some anglers do use them for panfish).
- They need to stay in a controlled environment — they won't survive being released into cold garden soil in winter.
European Nightcrawlers (Eisenia hortensis): The Versatile All-Rounder
European Nightcrawlers (often abbreviated as ENCs or Euros) are the second most popular composting worm, and they bring some unique advantages to the table.
Why European Nightcrawlers Are Great for Composting
1. They're larger.
European Nightcrawlers are noticeably bigger than Red Wigglers, typically reaching 4–6 inches at maturity. Their larger size means each individual worm can process more material.
2. They're dual-purpose.
This is where European Nightcrawlers really shine. They're excellent composting worms AND outstanding fishing bait. If you're a gardener who also likes to fish, or if you want to sell worms for bait as a side venture, Euros are a fantastic choice.
3. They tolerate a wider temperature range.
European Nightcrawlers generally handle cooler temperatures a bit better than Red Wigglers, making them a solid choice for composters in cooler climates or those who keep bins in unheated garages or basements.
4. They're good in garden soil.
Unlike Red Wigglers, European Nightcrawlers can actually survive and thrive when added directly to garden beds (as long as conditions are suitable). They help aerate soil and continue producing castings right where your plants need them.
5. They still produce high-quality castings.
European Nightcrawler castings are rich in nutrients and beneficial microorganisms, just like Red Wiggler castings. Your garden will love them.
European Nightcrawler Considerations
- They reproduce more slowly than Red Wigglers. Population growth takes longer, so it takes more time for your bin's processing capacity to increase.
- They are slightly more sensitive to bin conditions than Red Wigglers and may try to escape if conditions aren't right.
- They cost a bit more per pound in most cases because of their slower reproduction rates.
So, Which Worm Should You Choose?
Here's the honest answer: you really can't go wrong with either one. Both Red Wigglers and European Nightcrawlers are proven composting worms that will break down your kitchen scraps and produce beautiful, garden-ready worm castings.
But if you want specific guidance, here's what we recommend at Wired Worm Farm:
Choose Red Wigglers if:
- Your primary goal is composting kitchen scraps and creating vermicompost.
- You want to grow your worm population quickly.
- You're running a standard indoor or outdoor worm bin system (stackable trays, plastic totes, etc.).
- You want the most cost-effective composting worm to get started.
Choose European Nightcrawlers if:
- You want a worm that can compost AND serve as fishing bait.
- You plan to add worms directly to your garden beds for in-soil composting.
- You live in a cooler climate and want slightly more cold tolerance.
- You're interested in potentially selling worms for bait as a small side business.
Why Not Both?
Many experienced worm farmers — ourselves included — run bins with both species. Red Wigglers and European Nightcrawlers can coexist in the same bin. The Red Wigglers will handle the upper layers of decomposing food scraps, while the Euros tend to work a bit deeper. It's a productive partnership.
What About Regular Garden Earthworms?
We get this question a lot. People see earthworms in their garden and wonder, "Can I just use those?"
The short answer is no — common garden earthworms (like Lumbricus terrestris, the Canadian Nightcrawler) are not suitable for worm bins. They are deep-burrowing (anecic) worms that need to tunnel several feet into soil. They will not thrive in a shallow bin full of food scraps. They'll stress out, try to escape, and likely die.
Stick with species that are specifically adapted to composting: Red Wigglers and European Nightcrawlers.
Ready to Start Your Worm Bin?
At Wired Worm Farm, we raise healthy, vibrant composting worms and ship them right to your door. Whether you choose Red Wigglers, European Nightcrawlers, or a mix of both, you'll receive worms that are ready to eat, breed, and produce incredible castings from day one.
Questions about choosing composting worms? Reach out to us at Wired Worm Farm — we love helping people get started with vermicomposting.