While the red wiggler is a universal suggestion for a beginning composting worm, there are many situations that may mean a different worm will actually work out the best.
Below, I will compare and contrast six different kinds of composting worms. The worms I will cover will be the red wiggler, Indian blue, African nightcrawler, Alabama jumper, Canadian nightcrawler, and European nightcrawler.
The most important factor for choosing a worm is: Will it survive and thrive in the area you keep them?
If they're indoors, such as in a basement, this isn't too much of an issue—the comfortable conditions for most worms mirror the comfort of humans. Maintaining an environment that is moist enough for worms will likely be your driving factor in an indoor setup.
However, outdoors is a different story. All worms will die off if they get too cold, but two worm species are particularly intolerant to freezing temperatures. The African nightcrawler and Indian blue will die off if they remain cold for too long.
Jumpers are also somewhat intolerant to cold, but they also will burrow down deep into your compost to remain warm and are more likely to survive. Red worms and Canadian and European nightcrawlers tend to do better in colder environments, but freezing temperatures should be avoided.
That said, if your worms do die, the eggs that they have laid likely will survive. Once the temperature rises, the eggs will hatch and start a new population.
When choosing a composting worm, it is important to decide what the most important reason for vermicomposting in the first place. Generally, people start vermicomposting for a reason.
Some of the most common reasons are:
This is the reason I began vermicomposting. I enjoy gardening very much, but the soil here in Florida is very poor. It is mostly sand, with very little nutrients, and won't hold water for any length of time. This leads to needing to water very frequently to keep my garden healthy and bountiful.
While all worms produce castings, certain worms seem to do it more quickly than others. Of the smaller worms, red wigglers and Indian blues are particularly good at producing castings.
Blue worms have a somewhat higher reproduction rate than reds, but tend to be somewhat picky about their environment. Sometimes, it seems like the entire population decides to migrate elsewhere, fleeing the bin. This makes blues a questionable choice for an indoor bin, compared to red wigglers. If they do flee, eggs left behind will hatch and establish a new population, but that can take time to begin creating castings quickly again. Red wigglers are less temperamental and will stay put as long as the environment isn't inhospitable.
Of the larger worms, African nightcrawlers create castings the fastest and have a rapid reproduction rate as well. They reach maturity very quickly, and the castings are large. If your environment suits them, they are very good at making castings.
Jumpers generally feed on leaves and garden waste, though they can handle kitchen waste as well. They will burrow deeper than other worms. Canadian and European nightcrawlers reproduce slower and don't eat as much as the others.
Top casting producers (in no particular order):
Generally, worms for fishing should be larger to make hooking them easier. This makes the Indian blue a particularly poor choice, being the smallest of the worms we are ranking.
Red wigglers are only slightly larger than blues. They can be used for fishing, but the larger worms are considered better.
Canadian nightcrawlers are the old standby and are favored by many fisherman. They are the largest and thickest, making them particularly desirable. You can identify a Canadian nightcrawler from the flattened tail.
European nightcrawlers are also good, though they are somewhat smaller than the Canadian version.
Alabama jumpers are somewhat new to being used for fishing. They are very lively, but break apart easily. Due to their strength, if you have hand issues, such as arthritis, this can make hooking a jumper somewhat difficult. They are very fast!
African nightrawlers are also good for fishing. They can reach 12 inches in size, though they are not as large, overall, as a Canadian nightcrawler. They reproduce quickly though. So if you go fishing a lot, a population of African nightcrawlers will sustain you longer than any other bait worm.
Good worms for using as bait for fishing, in no particular order:
If your goal is to be more environmentally friendly and you want to reduce landfill waste, then your choices are going to be similar to casting production. That being said, avoid the Alabama Jumper.
The Alabama Jumper is an invasive species and should not be introduced into new areas if possible. It is already spreading and was endemic to my area before I even started worm farming. I regularly found them in my hot composting piles.
Top worms for waste disposal:
While every worm can be used to produce (and sell) castings, certain species are also desirable to other people and can be sold. Just like how I started vermicomposting for my plants, many people want to establish worm farms to produce castings for use in pots or to amend soil.
Gardeners will sometimes release worms directly into their gardens. They are also used as bait for fishing. Local bait shops, and even Wal-Mart, will carry worms to be sold as bait.
To maximize your profits, choosing a worm that will fill multiple niche needs will increase the likelihood of a sale. Red wiggler worms are frequently recommended for first time vermicomposters, because they are not too picky about the environment. They are less desirable for fishing, however, decreasing overall demand somewhat.
Canadian nightcrawlers, being the largest and most recognizable, are more in demand for fishing, but they reproduce at a slower rate and do not create castings as quickly. They also prefer colder temperatures, and should be cooled to 40°F to increase shelf life.
African nightcrawlers are a good compromise between the two but are vulnerable to cold temperatures. Refrigeration is actually detrimental, making African nightcrawlers very good for selling as well.
Best worms for making money: