Here’s a garden myth that just keeps circulating: that you can kill slugs by feeding them cornmeal. The idea is to pour a few spoonfuls of cornmeal into a jar, then turn it on its side before putting it out for the night. (The jar is to keep rain and dew out of the cornmeal.)
According to the legend, if you put out dry cornmeal, slugs will eat it and it will expand in their stomach until they die. Some versions say they’ll explode! (If only this were true: I’d love to hear the pop pop of slugs exploding.)
Like many garden myths, there does seem to a be a hint of logic behind the legend. After all, doesn’t corn meal expand when you add water? But then, just about everything dry will expand when you add water. But if you eat a cup or two of dry cornmeal (I’ll let you try that: it really isn’t my cup of tea!), then drink a cup or two of water, your stomach won’t explode. You’ll just digest it, period. And so will slugs.
In fact, cornmeal (dry) is often used to feed slugs and snails in laboratories. Surely scientist wouldn’t be feeding them something that causes gastric distress of any kind!
Instead of killing the slugs, you’ll therefore be making them fat and happy!
If you really want to get rid of slugs in your garden, read this: Slug Treatments That Really Work.
What About Ants?
You’ll hear the same thing said about ants: that if you put out cornmeal, they’ll eat it and die and/or explode. Yet, if you do this, you’re just feeding the ants, as they love cornmeal too. Read Garden Myth: Cornmeal Makes Ants Explode for more about this other garden myth.
I suppose if you’re the diligent person, you could use this as a method of enticing and trapping slugs for disposal. Or, it could just draw in more slugs who might see your tender veggies and go “oh hi, more munchies” ?
so what if you make a cornmeal slurry with a lot of salt?
You could try it, but I fail to see why a slug would try to consume anything containing a lot of salt.