Earthworms, AKA nightcrawlers, and red worms – known to many as “red wigglers” – are two of the most common species of worms for gardeners to increase the health of garden soil and producing compost, respectively. Both offer their own unique advantages for garden health, so it is natural to want to have both of their benefits at hand. Here’s some information on reasons why, and how, to keep earthworms and red worms together.
Can earthworms and red worms live together? It is possible to house both earthworms and red worms together, however, it is not ideal. This is because the two species are adapted for different population densities, temperatures, and soil depths.
Worms are an invaluable addition to your garden or compost bin. They are a crucial element to maintaining proper aeration to your garden’s soil, which prevents the soil from becoming too compact for your plants’ root structure. They also break down elements in the soil for optimal intake by your garden plants. Different worms do this with varying efficiency, so let’s see if the earthworm and red wiggler can work together.
The Benefits of Earthworms for Gardens
The common earthworm is the chunky little garden buddy that all green thumbs know good and well. After a rainstorm or maybe a generous watering of your garden, you’ll notice these little buggers surfacing from seemingly nowhere.
The four most common types of earthworms you will most likely run into are nightcrawlers, garden worms, manure worms, and, of course, red worms, (source) which we’ll talk about in the next section. The type recognized by most gardeners as the earthworm, however, is the nightcrawler (Lumbricus terrestris).
These worms get all the nutrition they need from the soil, and as they travel through the substrate feeding and defecating, their extremely fertile “castings” (waste) is the perfect nutritional supplement. In fact, earthworm populations have been shown to increase plant growth and health in independent studies (source). The tunnels that they form through the soil serve to oxygenate the plants’ root structure and creates habitat for microorganisms to contribute to plant health.
Earthworms are solitary in nature and can burrow up to six inches deep. Their castings are packed with key nutrients: phosphorus, calcium, nitrogen, and magnesium. In addition to aerating the soil, their tunnels also create routes through which water can percolate through the substrate, aiding in proper hydration of all of your garden fruits, veggies, and ornamentals.
The Benefits of Red Worms for Gardens
The benefits of red worms (Lumbricus rubellus) for gardens are, admittedly, nearly identical to those of earthworms (nightcrawlers). These worms are much slenderer than the nightcrawler, are redder in hue, and are generally smaller in overall body size.
However, even though the benefits will be largely the same when compared to the nightcrawler, red worms are better equipped to work and live in your compost bin or pile more than they are for your in-ground soil. This is because red worms have different preferences and environmental boundaries than nightcrawlers.
Red worms prefer to eat manure and decaying plant matter and are likely to eat anything that you put in your worm bin. They feed and prefer to stay within the top few inches of soil. Red wigglers are excellent consumers of organic kitchen waste and provide incredibly nutrient-rich worm castings which you can use in your garden or potted plants.
Now that you know how beneficial both earthworms and red worms can be, let’s talk about their cohabitation.
Can You Keep Earthworms and Red Worms Together?
Note: When most people discuss red worms, they are using the name interchangeably with that of “red wigglers.” Have no worries, this is the same worm, and the name “red wiggler” was earned simply because of the species’ secondary use as fishing bait.
There are both advantages and disadvantages to keeping red worms and nightcrawlers together in the same living space. Although it is possible to do so, there are some details to consider before you make your final decision, including the size of the worms and the container, the type of organic matter you will be using, and whether or not the compost bin/pile will be open to the air or closed.
The two are adapted for different environmental conditions, so it can be quite tricky to keep them together in the same container or composting system. However, with some creativity and care, you can make the perfect setup for both worms to be comfortable and thriving.
Why You Shouldn’t Keep Earthworms and Red Worms Together
It is possible to keep red worms and earthworms together in the same bin, but it is not ideal. This is because of the differences in the environment that the two species are suited for. The nightcrawler is a soil-dwelling worm that is used to living a solitary lifestyle, at a greater depth than the redworm – which lives in large groups nearer to the surface, and typically at higher temperatures. (source).
Red worms are also much smaller than nightcrawlers, meaning that they can be kept in higher densities in a closed compost bin than nightcrawlers (they are sold up to 1000 worms in one pack). This will be a lot better for your composting experience, as it will guarantee that your organic matter will be broken down at a faster rate than with just nightcrawlers or a mixture of nightcrawlers and red worms.
Additionally, if you are keeping nightcrawlers in a composting system, you will need a much larger containment setup than you would with red worms. This, again, is because of the solitary lifestyle of nightcrawlers. They need a bit more space per worm than red worms do.
Why You Might Choose To Keep Earthworms and Red Worms Together
If you have an outdoor composting bin with an open bottom or an outdoor compost pile, you can have both red worms and nightcrawlers.
I’ve never done this but I have read a lot about it. If your worm bin population increases too much it can result in the worms not growing as they should. You can thin out the population and put some in a traditional compost pile.
There are many ways both you and your worms would benefit from such a setup:
Both species would have access to conditions optimal for each of them: the nightcrawlers would be able to burrow deeply into the soil, as they can either burrow into the ground soil or deeper into the compost mix (since the openness of the container or pile allows for a large collection of compost/organic matter). The red worms can enjoy feasting in the top few inches where they are most content.
Keep in mind that, if you do mix the two species in one compost pile, you will need to add them at different depths. It is true that the night crawlers will be able to dig to a certain depth naturally, however, you don’t want to force them to do so by adding them at an unnatural depth, to begin with. In fact, don’t be surprised if you find earthworms showing up on their own in the lower parts of your compost pile. I see them routinely in my pile, burrowing up from the soil into the looser, more nutrient-rich matter.
If you are going to add nightcrawlers, add them to the bottom half or third of the pile before adding more organic matter, then as the pile grows you can begin to introduce your red worms into the compost. This will ensure that the worms inhabit every level of the compost and that all are housed at their optimal depths.
The one word of caution I would offer with this is that you should probably use the pile in a “cold” compost method, meaning not turning it very often if at all. Turning the pile allows the organic material to heat up but you are going to be displacing the earthworms if you turn the pile and move them to the top. By their very nature, worms are better suited for cold composting methods (source).
In the end, we are talking about two different species that thrive in distinctly different environments. It is possible for earthworms and red worms to live together but each would require certain conditions in order for their needs to be met. If you could provide a deep soil environment for the earthworms while ensuring shallow-soil feedings of the red worms then you could have the best of both worlds and be rewarded with a bountiful garden. Just understand that they will not happily cohabitate the same confined space.
To truly understand the factors of maintaining a successful worm bin, be sure to read How Long Can Red Wiggler’s Go Without Food? where we break down the five key elements of a balanced vermicomposting bin.