Published on May 14th, 2013 | by James Ayre


Earthworms Protect Gardens From Slugs, Research Finds

May 14th, 2013 by

Earthworms, when present in healthy numbers in a garden’s soil, effectively protect the plants there from being consumed by slugs, according to new research from the University of Natural Resources and Life Sciences in Vienna.

Garden Swiss chard

Image Credit: Vegetable Garden via Flickr CC

An interesting finding, for those of us that like to garden. Slugs can be quite the pest from what I’ve heard, though I’ve only had issues with them once — with regards to cucumbers. And that was remedied pretty easily by raising the plants off the ground.

HealthHeathen has more:

Even though the earthworms don’t have direct contact with the slugs or the plant growth above, they seem to very effectively protect the plants via increased nitrogen content in the plants, as a result of the earthworms being present. The researchers also found that with increased plant diversity the amount of damage that the slugs did to individual plants was greatly lessened.

The research was done by using large incubators to simulate grassland environments where “the researchers could regulate the diversity of plant species and time the introduction of earthworms and slugs.” What was found was that the presence of the earthworms increased the nitrogen content of plants and reduced the number of leaves damaged due to slugs by 60%. And interestingly, even when the total leaf area damaged was compared, the slugs ate 40% less at high plant diversity than at low. That’s a significant improvement.

Lead researcher Dr Johann Zaller, elaborates: “Our results suggest that two processes might be going on. Firstly, earthworms improved the plant’s ability to protect itself against slugs perhaps through the build-up of nitrogen-containing toxic compounds. Secondly, even though these slugs are generalists they prefer widely available food and in high diverse ecosystems slugs eat less in total because they have to switch their diets more often since plants of the same species are less available. Therefore gardeners are to help protect earthworms by increasing plant diversity in the garden in order to keep slug damage low. In order to elucidate the mechanisms behind these complex interactions, all parts of an ecosystem need to be investigated.”

Certainly something to keep in mind. And of course, earthworms provide much more benefit to gardens than simply keeping slugs away. It’s well worth it, for a variety of reasons, to encourage their presence.

Keep up to date with all the most interesting green news on the planet by subscribing to our (free) Planetsave newsletter.

Tags: , , , , , , , , ,

About the Author

's background is predominantly in geopolitics and history, but he has an obsessive interest in pretty much everything. After an early life spent in the Imperial Free City of Dortmund, James followed the river Ruhr to Cofbuokheim, where he attended the University of Astnide. And where he also briefly considered entering the coal mining business. He currently writes for a living, on a broad variety of subjects, ranging from science, to politics, to military history, to renewable energy. You can follow his work on Google+.

Back to Top ↑
  • Connect!

  • 5 Ingredients For A Green Life

    Green Living Info
  • Advertisement

  • 7 Ways to Go Solar

    Solar Power Growth
  • 8 Electric Car Benefits

    electric car benefits
  • Advertisement

  • 10 Bicycling Benefits

    Dutch Bicyclist
  • Save $10,000/Year Riding Transit

    transit savings
  • Advertisement

  • Electric Cars List (US & Europe)

    Solar Power Growth
  • Top Posts On Planetsave

  • Free News from Planetsave!

  • Tell us Your Sustainability Story!

  • Go Solar

    Want to save the planet? Want to live green? Want to save some serious cash money? Go solar! The cost of solar panels today is at a serious low. Go and get a solar quote and home solar report for your home... and then help save the planet!
  • Search the IM Network