When I first started my vermicomposting bin, I knew close to nothing. The biggest question I had were what worms should I use and where I can get them. So, after some researching and testing a specific type of worm, I found a good answer.
The best type of worms to use for composting are red wigglers and redworms. These two worms are epigeic, which are those that live close to the surface. Since composting also usually takes place on the surface, epigeic worms make great composters. Earthworms (or garden worms) live deeper and don’t compost well.
Worms are an important but unseen feature of gardens, and they’re amazing decomposers. However, there’s a difference between being a good decomposer and being a good composter. This difference mainly has to do with the depth at which the decomposition takes place.
This begs the question: which worms can function as compost worms?
What Kinds of Worms Can You Put in Compost?
The best composting worms are epigeic, which includes red wigglers, redworms, brandling worms, and African nightcrawlers. Epigeic worms live on the surface, such as in leaves, manure, and other loose environments. Surface soil is where most of the composting usually occurs, making epigeic worms the best choice.
There are three main types of worms: Anecic, Endogeic, and Epigeic.
Epigeic worms live on or near the surface and swarm around microbe-rich organic wastes, where they find plenty of nutrients to decompose such as leaves, decomposing branches, and other organic materials. Worms that like to live deeper, such as earthworms, often won’t touch the surface compost and aren’t practical to use.
Epigeic originated from the Greek language, meaning “above the earth”. Similarly, composting needs to take place on the surface of the soil, rather than below the surface—where the majority of worms live and feed.
Because of this, there are only a few types of worms that can be used as successful composters. In fact, out of thousands of species, only several species are good for composting and available for purchase.
Here are the 6 best kinds of worms to put in compost piles (or bins):
- Red wigglers
- Redworms (AKA manure worms)
- Brandling worms (AKA “tiger” or “trout” worms)
- European nightcrawler
- Indian or Malaysian blue worms
- African nightcrawlers
The most common composting worms in the US are red wigglers. This is the kind that I have and the kind that most use for their composting bins. Red wigglers are fairly easy to get and are inexpensive (I bought mine at PetSmart for $14. Check out my video at the bottom of this post for how I put together my worm bin in just a few minutes).
Redworms are also a popular choice in composting and do a similar, if not the same job as red wigglers. If you don’t have any red wigglers available in your area, try checking for redworms.
Brandling worms, also named “tiger” or “trout” worms, are well-known for their ability to process manure. If your compost has a lot of manure in it, try to get your hands on these worms.
The European nightcrawler is not as commonly used as the red wiggler and redworms, mainly because they require cooler temperatures. Since compost mainly occurs on top of the soil, and organic decomposition generates heat, the surface soil can get pretty warm (and often exceed 135ºF). Because of this, even though European nightcrawlers live closer to the surface, they’re not ideal to use in most composting setups.
On the other hand, Indian or Malaysian blue worms prefer tropical climates. These worms are often visually confused with red wigglers, but their behavior differs slightly. Indian worms are sensitive to barometric changes, and they’ll often surface as storms approach. This can mean easy pickings for predators or escapes from your worm bin (if you don’t have a good cover).
African nightcrawlers are a good choice for composting worms as they can eat up to 150% of their weight daily. So, if you have 1lbs of worms, you can turn 1.5lbs of compostable materials A DAY. Like most other composting worms, they prefer warmer temperatures, and will even start to die once they reach 60ºF. This makes them a bit less desirable than other worms. If you decide on using African nightcrawlers for your composting, try to keep the soil between 75-85ºF.
Whichever epigeic, or composting worm you choose, know that these types of worms aren’t the strongest burrowers, so they typically won’t survive well in the more dense soil of a garden—especially if the soil’s content has more clay. If you’re looking for garden worms, you’re better off using the humble earthworm (more on them later).
If you’d like help identifying the different types of worms, and would like a visual, check out this cool guide by trees.com.
Are Garden Worms Good for Compost?
Garden worms, or earthworms, don’t make good composting worms since they prefer to feed off of the already decomposed matter deeper in the ground. For the best results, use surface-dwelling, or epigeic worms such as red wigglers or redworms. These worms move more horizontally through the soil—eating surface food.
Worms that are good for composting, like red wigglers and redworms, are more likely to be found near natural compost piles or rotting logs than in gardens.
While red wigglers like eating freshly fallen leaves, fruit, and other organic material, earthworms prefer to eat the deeper materials. Often, this matter has been decomposing for a while, usually breaking down into smaller nutrients.
Still, earthworms have their place, adding nutrients to the soil (and therefore—plants) through their castings and burrows in the soil.
Earthworms also provide aeration for the plants’ roots and increase the water intake of soil with their frequent burrowing. This is incredibly important if you’re looking to capture more rainwater on your property and decrease topsoil erosion. These burrows also carry nutrients further into the soil, which delivers nutrients directly to the plant’s roots.
On the other hand, compost worms stay on the surface, eating fresher organic matter. This makes them not as helpful in gardens. They also don’t tunnel as deeply, which means less aeration and water penetration in the soil.
While it may seem easy to simply toss a few garden worms into a compost bin, it most likely won’t bring good results. They’re much more valuable in your garden’s deeper soil.
If you’d like to learn more about earthworms, and the benefits they bring to gardens, you might be interested to know that Charles Darwin conducted some studies. He was one of the first to show that they’re not pests but in fact beneficial aspects of a garden.
How Many Worms Should I Get for Composting?
If you have a small compost bin, start with 1-3lbs of worms. If you have larger compost bins or piles, consider getting 10-50lbs. Since most composting worms, such as red wigglers, can double in population every 60 days, you can start with a few pounds and soon get your desired amount.
Where Can You Buy Worms for Compost?
Because worms can be difficult to identify, it is a good idea to buy them from a reputable source.
Here are the three best places you can buy compost worms:
- Pet stores
- Nurseries or Garden stores
Keep in mind that these worms are most likely going to be red wigglers, which isn’t a problem since they’re one of the best for composting. However, if you’re looking for a different type of worm, it’s best to call ahead to see if they carry them.
I got my red wigglers from PetSmart (they use them as fish food). I bought a few packs of them for $14. Since I knew the worms would multiply quickly, that’s all I needed.
To see how I set up my worm bin in about 5 minutes (and for under $19), you can check out a short video I made below.
To get the most out of your compost pile, you first need the right species of worm. Red wigglers and redworms are best, but African nightcrawlers and brandling worms will work too.
A compost bin can be a great help to your garden and is a good way to get rid of food waste as well, so putting in a little effort to set the compost pile up and maintain it is well worth it. I spend about 5 minutes every 1-2 weeks tending to my worm bin.
Worm bins can also be used in apartments (this is how I started). Don’t worry, worm bins are pretty easy to set up, not messy, and don’t smell.
Since they typically don’t have an odor, they can be kept inside if the temperature is about to swing and get too hot or cold. For example, I kept my worm bin inside for the first several months that I had it (since it was winter) and it didn’t smell at all. When I took off the lid, it just smelled like fresh, earthy soil.
Bringing your worms inside can save them and avoid you from having to start fresh. If you’d like, you can even keep the worms and your compost pile going all year long.
The rule of thumb is that most composting worms will eat half their weight each day. To keep your worms alive and happy, you should be feeding them table scraps at least weekly. Avoid adding citrus, onions, and animal products such as dairy, meat, and bones.
If you’re starting your worm bin, or pile, with 1 pound of worms, you’d need about half a pound of food scraps each day (just be sure to check that they’ve finished their food before adding more!).
For more information about worm bins and worm castings, you can check out my recent post about if worm castings can replace fertilizer.