The Best Worms for Composting
In this article, we give our recommendation for the best worm species for composting so that you can make the right choice for your worm farm.
Reading time: 8 mins
Finding the best worms for composting can sometimes be tricky for a beginner. There are a number of species suited for composting, but each comes with its own characteristics that help them thrive in certain environments more than others.
As you may already know, composting worms decompose organic materials (such as food scraps) into nutrient-rich worm castings. Although worm castings are considered waste by worms, they are a valuable resource for gardeners. Traditional compost is deficient in critical plant nutrients such as nitrogen, phosphorus, and potassium. Vermicompost is rich in these elements. It also contains bacteria that aid in the growth of plants. In this article, we will discuss which species are considered the best worms for composting.
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There are currently around 6000 recorded species of earthworms on the planet. However, only a small handful of these are suitable for use in composting, namely those that live and feed in the top layers of soil. Earthworms are categorized into 3 main sub-groups: Anecic, Endogeic, and Epigeic.
Anecic worms are those that love to burrow vertically down, deep into the soil. They play an important role in soil health as they re-mineralize depleted topsoil layers and provide irrigation channels for water to flow deeper into the ground. This makes them the perfect worm for gardens, but not so suited for composting bins. Since they like to burrow deep into the soil they don’t feed on the surface where all the decaying organic matter is located.
Endogeic worms can be considered to be medium-depth burrowers. They don’t go as deep as Anecic worm species but still like to live well below the surface. These worms feed below the surface and create horizontal burrows between the topsoil and subsoil layers. Again, since they prefer to feed farther down, they don’t make the best composting worms.
The last group are known as the Epigeic variety, which means top-layer dwellers. These worms love to live amongst the decomposing leaf litter located on the surface and create fertile topsoils. The soil is often softer and less compact on top than it is deeper below the surface where some of the other varieties of worms like to live. This makes them the ideal choice for composting, but not for putting in your garden. Epigeic worms often have voracious appetites and will eat just about anything organic – which is great news for us!
So what are the best composting worm species?
The following worm species are the most common types of composting worms that you’ll be able to find. Keep in mind though that, like all worms, some are better suited to different types of environments than others.
1. Red Wigglers
The red wiggler is by far the most popular and widely available composting worm in the United States and Canada. You’ll also find them referred to as Tiger worms, or just simply as red worms. They are a fantastic choice for vermicomposters for a number of reasons.
Unlike some other worm species, red wigglers can work effectively in a wide range of temperatures (55-95F). This ability to withstand a wide range of temperatures helps them to reproduce quickly, as their cocoons are also very resilient.
Red wigglers are also less expensive to buy than other species, retailing for around $50 for a pound of worms. They will eat almost anything organic, but remember to keep the conditions balanced by occasionally topping up their bedding with shredded newspaper or coconut coir.
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2. European Night Crawler
European night crawlers are quickly becoming a popular worm farm breed. Just like red wigglers, they are also great for composting. The European night crawler is a dark pink or red worm that grows to be near twice the size of red worms.
Euros are easy to raise and reproduce quickly, making them a suitable choice for both new and experienced worm farmers. Unlike red worms, however, they do prefer cooler temperatures around 60F to 70F.
Euros are tough, eat all kinds of kitchen scraps, and can grow to be quite large. If you want to raise bait worms, the Euro is the way to go. European night crawlers are also colony dwellers, and they don’t mind colliding with each other in the worm bin.
Just keep in mind that if you want Euros to fully mature into excellent bait worms, they’ll need plenty of freedom to grow.
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3. Indian/Malaysian Blue Worms
Indian blues, or Malaysian blues, are used widely in parts of Asia, Australia, and in other tropical countries. When this little composting worm is placed into the light, it has a distinctive blue sheen, hence the name.
Blue worms are slowly making inroads into North America as more worm farmers search for the ultimate composting worm. That being said, we don’t believe the blue worm’s cold tolerance to be very strong.
Indian Blue worms thrive best in temperatures ranging from 70F to 80F. If you live in a state such as Florida, you should have no difficulty raising them in a tropical climate.
Despite their tropical origins, it’s a good idea to keep your blue worms out of the sun and provide plenty of shade if the temperature rises beyond 90F. If the conditions in their bins aren’t ideal, blue worms have a habit of leaving.
We’re not talking about a few dozen worms crawling out of the container; we’re talking about hundreds of worms at a time. A mass exodus like this can lead to a very messy situation. Provided you keep conditions in the composter suitable for the worms, you really shouldn’t find this to be an issue. Something to keep in mind though in your hunt for composting worms.
4. African Night Crawler
African night crawlers are native to the warm parts of West Africa, but they are currently used as composting and bait worms in many parts of the world. African night crawlers are increasingly gaining popularity among vermicomposters due to their ravenous appetites and capacity to breed swiftly.
However, because of their warm-weather origins, ANCs cannot endure the same climatic conditions that red worms and European night crawlers can.
According to scientific studies, ANCs develop faster than red worms. Newly hatched ANCs attain sexual maturity relatively quickly meaning that they can reproduce a lot faster than other species. They can mature into adult breeders in as little as 5 weeks under optimal conditions.
African night crawlers can create up to 3.5 cocoons per week on average. Similar to most composting worms, ANCs come up to the surface of their bedding to eat decomposing matter. Though typically you’ll find ANCs working at different depths to red worms.
RELATED: African Night Crawler Fact Sheet
Our recommendation for the best worms for composting
Red wigglers are our recommendation for the best worms for composting. It is a tough worm with a big appetite, which is great for getting through household waste. Red worms reproduce quickly and thrive in a wide range of temperatures which makes them a hassle-free option for beginners.
Thanks to its adaptability to different climates and ability to reproduce quickly in them, the cost of red wigglers is consistently lower than European nightcrawlers and significantly lower than the African nightcrawler.
That being said, definitely don’t rule out the others if you live in a climate more suited to those particular species. For the majority of conditions though, red wrigglers will definitely be able to get your vermicomposting journey underway.
If you live in North America and are looking to purchase composting worms, check out Uncle Jim’s Worm Farm for high-quality red wrigglers and European night crawlers. They ship to nearly all of the United States, and a few select international locations. Alternatively, you can purchase them through Amazon here.
So there you have it. Our recommendation for the best worms for composting. They should get you well on your way to producing high-quality worm castings for you to either sell or use in your garden. Happy worm farming!
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