05/27/2026
Slug Week science!
We know many gardeners swear by crushed eggshells for keeping slugs away from plants. Unfortunately, the science just doesn’t really support it.
Research has shown that slugs are perfectly capable of crawling right over crushed eggshell barriers, even the sharp ones. As horticulturist Dr. Jeff Gillman of the University of Minnesota put it, slugs had “no problem traversing across the nasty shells.”
That doesn’t mean eggshells are useless — they can still be added to compost and they can contribute calcium to soil over time — but if you’re relying on them as your primary slug defense in a damp Oregon garden, you may be disappointed.
Sometimes gardening myths stick around because we really want them to be true. (Trust us, we get it.)
