“What is the best worm for vermicomposting?” – Bill C.
That is a great question, and something I’m sure many people wonder about.
It is one of those questions that can be answered with a “it depends” – but of course my job here is to provide you with a decent response so I won’t just leave it at that! 🙂
One thing it depends ON is your primary objective – what exactly are you trying to do?
The term ‘vermicomposting’ implies that you are interested in converting wastes (such as kitchen scraps) into a rich compost, but it’s a term that often gets used for a wide variety of related things.
If you are for example REALLY keen to produce worms you can use for fishing, or even sell as bait, my answer might be different than if you are just a composting purist, looking for the fastest processing times and the best end product.
According to well-known vermicomposting researcher, Dr. Clive Edwards (emeritus professor at Ohio State University), the Red Worm (Eisenia fetida) is by far the most versatile composting worm available. He has conducted research comparing this worm to other composting species, and found it to outperform all the others (overall).
They have a very wide range of temperature tolerance (surviving temps ranging from the freezing mark all the way up to 35 C / 95 F), are very tough and tolerant – withstanding a wide range of conditions, they can process a wide range of waste materials very readily, and they’ll increase in numbers quite rapidly under ideal conditions.
The red worm also happens to be the most widely used worm for vermicomposting in the world – yet another indication of their extreme versatility. I’ve used this worm myself for many years now, and I’ve been very impressed with it!
That being said, I only recently started composting with European Nightcrawlers (Eisenia hortensis) – a close relative of the Red Worm. Based on what I’ve read, they’ve never sounded particularly appealing for someone interested in pure composting potential.
It is suggested that they reproduce more slowly than Red Worms, take longer to mature, and just aren’t as efficient at processing organic wastes. I know there are worm farmers who would disagree with this wholeheartedly, and I am starting to see why.
Thus far I have been very impressed (and pleasantly surprised) with my Euros. If you have any interest in using your worms for fishing, then I would say with 100% certainty that the European Nightcrawler would be the ‘best’ worm for you.
They are considerably bigger than Red Wigglers, but not as big as Canadian Nightcrawlers (which as I recall can be somewhat cumbersome to get on a hook), but the beauty of it is that they can be raised very easily in the same manner as Red Worms.
This summer I am hoping to really put them to the test in the composting and breeding department to see how they stack up against their smaller cousin.
So what about other worms?
I certainly don’t mean to imply that Red Worms and European Nightcrawlers are the ONLY composting worms out there. Two other well known examples that should also get a mention are the African Nightcrawler (Eudrilus eugeniae) and the Blue Worm (Perionyx excavatus). Both of these worms offer excellent vermicomposting potential, but primarily in warmer parts of the world.
Under their respective ‘ideal conditions’, Africans and Blue Worms can outperform E. fetida, both in terms of waste processing speed and reproductive potential – but unlike the Red Worm, their ideal range is quite narrow. Both reportedly start to die once temps dip below 10 C (50 F) or get warmer than 30 C (86 F)!
There are also claims that both of these species have a tendency to roam from worm beds, often for no apparent reason. I haven’t raised either species myself – so I can’t verify or deny these claims with any certainty.
Hopefully I’ve helped to point you in the right direction, Bill. Again, in my humble opinion, your best bet is to go with either the Red Worm (Eisenia fetida) or the European Nightcrawler (Eisenia hortensis), or what the heck – why not try both! 😉