It’s a little known fact that Charles Darwin’s last book was about earthworms and their value to both geology and agriculture. It’s no wonder he turned his attention to such humble creatures. Few things in nature are as effective at improving tilth and aeration as the earthworm, all while enriching the soil with its castings. Needless to say, earthworms should be a welcome addition to just about any in-ground garden or large gardening container.
Adding Earthworms to the Garden
Don’t just dump the worms from your last fishing trip into your garden. In many cases, those worms are Canadian nightcrawlers or other varieties from northern climes, and they can’t easily handle the heat in many states. (That’s why they can survive in your fridge for so long.) Don’t dump the red worms in your vermicomposter in your garden, either, at least not without getting advice from an agricultural professional.
Earthworms tend to be gentle invaders, but species that are too foreign may quickly die out, or at least require multiple applications before they take hold. If your soil is currently lacking in earthworms, contact your local agricultural extension agent for advice on which species are native to your area, and where you can get them commercially.
Keep Feeding Earthworms
If you live in a dry, arid region and decide to stop gardening for a while, you’ll need to provide some food for the worms if you want them to be there when you start up again, since they won’t be getting the by-products of your gardening efforts. A nice spread of mulch or grass clippings should be sufficient, especially if you can work it into the soil a bit. Otherwise, sow some grass seed over your garden area until you can get back to it, as this provides both food and shelter for the worms.
(And by the way, the Darwin book? For its time, it was a bestseller—and initially sold better than the work for which he’s best known, The Origin of Species.)
Want to learn more about earthworms for the garden?
How to Increase the Number of Earthworms in Your Garden Soil: Our own gardening tips for increasing earthworms.
Earthworms from Colorado State University Extension
Crops and Soils- Earthworms from Penn State Extension