Get to Know These Types of Composting Worms
The world of earthworms is a big one with about 3000 species in total across the world and over 100 native to just the United States. If you are thinking of composting with the help of worms, which ones might you want to choose? Could you use the same worms that you find in your backyard? You bet! but you might not optimize your compost production or if you are into worm breeding (like some of us) yield new stock as quickly. Here we’ll try to give you a short rundown on what to choose if you want to get started vermicomposting and collect your very own organic worm poop!
Categorizing Earthworms. Which is Best for Vermicomposting?
Now all earthworms are biologically similar when it comes down to breathing, burrowing and birthing, though they all have their own evolutionary behaviors that make them act somewhat differently. Some may prefer different foods, soils or temperatures depending on the species. What does this mean for you? When working with these different kinds of worms you’ll experience different feeding habits, burrowing structure, overall movement and a unique personality that may or may not suit your needs when intending on harvesting. So what can you expect to find out there?
Anecic (Rise from Earth) Worms
These are deep earth dwelling worms. The most common that you’ll probably see here in the U.S. is the common nightcrawler (Lumbricus Terrestris) also commonly called the ‘canadian’ nightcrawler or dew worm. These are the long fat brown earthworms native to the northern U.S. and Canada which you can usually grab from the baitshop for fishing. Nightcrawlers can grow up to 14 inches in length! Now that's a big worm. These are usually great for that purpose because of their size and powerfully wiggly behavior. In the wild these worms will burrow as much as 6 ft into the earth and drag dead vegetation from the top soil layer down with them.
If you’ve ever seen little mounds of dirt around what seems to be a hole, this is not just dirt but actually anecic worm castings. Pretty cool right! Because of the solitary nature of these worms in their individual burrows they will not mate very often in relation to other worm species about 1-2 times a year. Their very active behavior also has a downside: they like to move! Hence the name. Nightcrawlers have a tendency to travel far and can be escape artists if you have them in an enclosure that is not completely secured. This and their long breeding time usually keeps them from being a top pick for vermicomposters.
Endogeic (Within Earth) Worms
These are medium earth dwelling worms, essentially they live and feed within the soil layer. Their ecological importance is to feed on organic matter within the soil layer itself, burrow and process the soil, mixing it and enhancing the bioavailability of the minerals and other nutritious compounds for plants to grow. Similar to Anecic Worms these worms burrow but not as deep only on the top layer of soil about 1-2 feet at most. They are usually living in conjunction with their anecic counterparts to cover the whole root system. A common species is the grey worm (Aporrectodea) and has many varieties that have settled themselves all across the United States and Europe. Some species of these worms are also called nightcrawlers and for good reason they also are a bit more active than other worms. This leads to the same problem, their need for space and deep burrowing nature is not as optimal for casting production or worm harvest.
Epigeic (Upon Earth) Worms
These are the surface dwelling worms. This type of worm doesn't burrow like the other two and live within the top layer of soil. Epigeic worms usually won’t be found beyond a foot below in the soil layer. Most of these worms like to eat and live within the same layer of organic material feeding on dead plant matter and other organic compounds such as animal manure and fungi. The red head worm (Lumbricus Rubellus) is a common example and can be found all across the world specifically here in North America but in Europe and Asia as well. From forest floors to farms, wherever there is a lot of decaying organic matter you are likely to find these guys. These worms breed quickly and eat through organic matter even quicker. These types of worms are usually a fan favorite for aspiring vermicomposters as they keep their numbers high and generate the most castings.
So what types of composting worms can you get your hands on?
The Red Tiger Worm (Eisenia Fetida)
One of the two worms marketed as “the red wiggler”, the tiger worm is a robust and well mannered worm that is a top pick for most veteran composters and those just getting into the trade. It is called the tiger worm due to its distinct orange stripes that separate the segments of its body near its tail and head. From a glance it looks like other red worms like Lumbricus Rubellus with a light red color but under the right light its distinct markings give it away.
Overall
Fast eaters and not too picky
Average breeders (1 cocoon per week/ 4-6 egg per)
Comfortable in a wide range of temperatures (40-90 degrees)
Don’t like the light and beare more likely to stay within their bin.
Very Epigeic; Has a tough time consuming deep layers of compost.
The Common Red Worm (Eisenia Andrei)
A close relative to the tiger worm, so close that vermicomposters usually consider them to be the same worm. Nearly identical, Andrei is usually a bit darker red than the tiger worm and lacks the same vibrant orange banding. Though these worms may look the same, move the same and live in similar environments these guys are more prolific breeders.
Overall
Fast Eaters and can manage more nitrogen rich foods (greens)
Prefer slightly warmer temperatures (50-70 degrees)
Very Fast breeders (3-4 cocoons per week/ 6-8 egg per) when conditions ideal
Generally the same as Eisenia Fetida when it comes to care and activity
The European Nightcrawler (Eisenia/Dendrobaena Hortensis)
Another close relative to the red tiger worm, the European nightcrawler is a larger darker version that prefers a more fibrous diet. Similar to its canadian cousin this worm has a more wiggly nature and will burrow deeper into the soil than other composting worms. Like other nightcrawlers this worm is a great choice as a bait worm. Unlike its canadian cousin though this worm prefers a wider and warmer range of temperatures and can reproduce a bit faster. This makes them a very viable choice for some composters.
Overall
Prefer more carbon rich foods (browns)
Comfortable in a wide range of temperatures (45-80 degrees)
Slow breeders ( 0.8 cocoons per week/ 1 egg per)
More Anecic; Good for multilayer compost, can struggle in short horizontal beds
The African Nightcrawler (Eudrilus Eugeniae)
This worm is originally from west africa but has been imported to different parts of the world to be used as both a bait worm and a composter. This worm appears dark gray with reddish purple accents and can grow as long as 10 inches. Unlike its European and American counterparts this worm is epigeic and prefers a much warmer climate. These large worms are fast breeders and fast growers under the right conditions but population health can be very temperamental in subpar conditions. This worm is a great casting producer and is top choice by many veteran composters.
Overall
Veracious Eaters and not too picky
Fast breeders (2 cocoons per week/ 2-3 egg per)
Very Epigeic; Will require top layer feeding more often
Are difficult to maintain if temperatures fluctuate too low and will be better for warmer climates (65-95 degrees)
The Indian Blue Worm (Perionyx Excavatus)
Another worm that is commonly mistaken for the red tiger worm, the indian blue is an exotic worm that fills a similar ecological role but from another part of the world. Morphologically the indian blue looks similar and is the same size as the red tiger worm but can be identified by a blue/purplish sheen on their tails and head. Another way to tell the difference visually is their smaller and more streamlined clitellum. These worms move more like their nightcrawler relatives and are far more active than other epigeic worms and have a tendency to migrate when conditions get colder and wetter. Like the African nightcrawler the blue worm is more comfortable in warmer climates and will eat just about anything you give them. Their rate of reproduction is also unmatched compared to other worms. Because of this many vermicomposters use them as their staple casting producer.
Overall
Very fast eaters and can manage more nitrogen rich foods (greens)
Fastest Breeders ( up to 19 cocoons per week/ 1-2 egg per)
Comfortable in most but prefer slightly warmer temperatures (50-90 degrees)
Have nightcrawler tendencies and may try to migrate out of their bin or bed when conditions get too wet or sense a change in barometric pressure
How to make the right choice for you?
Given what we now know about our wiggly friends the choice of which worm species to pick from really comes down to a few factors:
1. Are you new to vermicomposting?
2. What will your worm's environment look like?
3. What will you be feeding your worms?
4. What is your need for the worms?
Person 1: You are new to composting and would like to start a bin in your garden. You live in the central United States which can fluctuate in temperature greatly. You plan on composting scraps from your garden with other food waste from your home included. You do not want this to be a low maintenance venture and more “set it and forget it”.
Suggestion: The red wiggler (both species) may be the right choice for this person due to their low maintenance and ability to survive in both cool and warm temperatures. These worms are also good at eating away at new additions to their compost bin quickly.
Person 2: You are an experienced composter and are looking to increase your casting yield for the upcoming summer. You live in a warmer state like Florida or have the luxury of keeping your worms in a temperature controlled environment.
Suggestion: This person may see more benefit composting with an exotic worm like the indian blue or african nightcrawler. The controlled/ warm environment will cater to both of these worms strengths and allow the worms to thrive. These worms will want to eat more and reproduce much quicker making it easier to see more compost turnover.
Person 3: You run an organic produce specialty shop where you sell heirloom fruits and vegetables. You are looking for a way to increase the nutrient density of the soil your crops grow in without using synthetic fertilizer.
Suggestion: This person may benefit from a mix of worms. A combination of nightcrawlers and red worms can work on the many levels of the soil the plants grow throughout. This would break down dead plant matter and turn the soil. This multilevel approach will naturally fertilize soil by adding nitrogen rich compounds through castings and foster the growth of beneficial microbes in the soil.
Hopefully from here you can make a more educated choice before grabbing a few pounds of worms you might not know anything about.
If you are still stuck on what decision to make, what do we think is the best choice overall?
The Red Wiggler is the best at what it does. This worm can do it all, literally. They are really difficult to kill based on the environment alone and are not particularly picky when it comes to what you feed them.
We love all our worms, but if you want to make a decision that you definitely won't regret the Red Wiggler is the perfect choice for any aspiring or veteran vermicomposter!