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European Nightcrawlers

The European Nightcrawler's (ENC's) scientific name is Eisenia hortensis, but it is also known as trout worms, super reds and giant red worms. These worms can grow to between 3 and 8 inches in length, which makes them much larger than many of their more common cousins such as Red Wigglers (Eisenia fetida and Eisenia andrei).

ENC's thrive in temperature between 15°C to 25°C. In my personal experience, they are able to tolerate ambient temperature as low as -10°C so long as the bedding does not freeze over. Heat is more dangerous to ENC's than the cold. Try to move your worms to a cooler spot when ambient temperature reaches 30°C and monitor for signs of distress. You may also want to decrease the amount of food given each feeding as decomposing food generates heat - a large feeding can generate enough heat in the summer to kill your worms! Placing a frozen water bottle in the bedding can also help them deal with summer heat. 


European Nightcrawlers can raise in large, opaque plastic totes. I recommend a tote larger than 30 L volume for bait size worms. Contrarily to popular belief, you do not need to drill holes at the bottom – your bin should never run so wet that liquid comes out of the bottom. Air holes on the lid is recommended if you will be closing the lid. You do not need to use the lid for your worm bin – simply put a layer of fabric or other breathable material on top of the bedding can work wonders.


Your worm farm does not need any soil. The worms lives in organic materials, most composters known it as “browns”. Most commonly used bedding are: dried leaves, shredded newspaper/cardboard, coco coir[1], and peat moss. The bedding needs to be moistened for the worms. The ideal wetness of your bin should be similar to a slightly dampened sponge – when you squeeze it, only a few drops of water should come out. Peat moss may be a cheaper alternative for those that do not want to shred newspaper/cardboard. However, because peat moss is naturally acidic, you will need to adjust the pH to neutral prior to adding it to your worm bin. Otherwise, you may notice the worms trying to escape the bin as they have a preference for pH neutral environment. You can adjust the pH of the peat moss with dolomite lime. Do NOT use “hydrated lime”, “builders lime”, or “slaked lime” since these are caustic and not worm-friendly.


The worms will eat a variety of organic waste such as vegetable scraps, fruit peels, coffee grounds, and used tea leaves. Avoid overly acidic food such as lemons and onions, meat, dairy, and bones. Overfeeding is the number one mistake every worm farmer makes at some point in their career. It can cause overheating of your bin and kill all your worms. Start with a small amount of food and only feed when the food is mostly gone. The worms do not have teeth and will have to eat the food when it starts rotting. To help speed up the decomposition process, consider freezing the food scraps before feeding. A bonus to freezing the food scraps is elimination of potential fruit fly infestation, as the fruit fly eggs will not survive freezing temperature. It is not necessary to thaw the food prior to feeding. In fact, feeding frozen food directly to the worms in the summer can also help decrease the temperature in the bin.

Harvesting Castings:

Overtime, the worms will turn the organic materials (bedding and food) provided to them into worm castings, or worm poop. These are amazing natural fertilizer for your garden or lawn. If you do not garden, you may gift it to friends/family who does. Pick out any worms/worm cocoons before you use it in the garden. You will need to harvest your bin’s castings every 4-6 months. If you allow the castings to build up in your worm farm, the bin condition may become too moist and dense, which will lead to smaller worms and decreased reproduction.


[1] TriCity Worms sells Pre-Rinsed and pH Buffered Coco Coir bricks for $5.50 each (before tax & shipping). When hydrated, each brick will provide 10-12L of ready to use bedding. Discount may be applicable for large or subscription orders.