QUESTION: Can I use regular earthworms for composting? And how do I do it? – Frances N
ANSWER: First of all, unless you’re using the vermicomposting method, you don’t need to worry about obtaining worms for your compost heap. A few worms are bound to wiggle in on their own, and they’ll come and go as they please, but you don’t need to supervise them or make sure your compost has worms in it. Invisible microbes in your compost will do the work of breaking its components down, so you don’t need to add worms in order to get things done.
However, if you are using vermicomposting and need to source some worms for your worm farm, earthworms are not your best bet. Most vermicomposters use red wigglers (Eisenia fetida) or redworms (Lumbricus rubellus), and with good reason. The compost pile heats up much more than everyday soil would because of the microbes at work breaking down its ingredients. A compost heap can get so hot that it will kill regular earthworms, but red wigglers and redworms do better in the compost’s hot conditions. (Red wigglers can tolerate temperatures that range from 32 to 95 degrees Fahrenheit.)
Another important consideration is that standard earthworms don’t feed on food and paper waste or the other components that make up the compost pile. They actually get their nutrition by soaking it up through their skin, from the soil they move through or, if they’re rooting around in someone’s compost heap, from the substances in the compost. That means although earthworms will happily slink through your compost (as long as it isn’t too hot), they won’t be contributing to the process of decay that produces the final product.