I have been thinking about writing this article on garden slug control for nearly a year now and I wanted to start with a joke but I just couldn’t do it. Slugs are just plain gross! They are related to both the main ingredient of the French delicacy, escargot, and the maritime favorite, clam chowder, but you will not find me experimenting with these in the kitchen!
Things really are not so bad in Minnesota. Western Oregon and Washington are home to the banana slug, which is reported to reach eight inches long leaving a trail of slime a half inch wide. Our slugs seldom achieve one-and-half-inches of length.
Slugs are more than just a visual problem. They will eat holes in your peppers, tomatoes and strawberries. They can camp out in heads of lettuce and cabbage, leaving slime and causing rot. They also like hostas and create holes in the leaves and they can be especially hard on young seedlings. Some people see the holes in hosta leaves and apply an insecticide that does nothing to the slugs that are not seen because they feed mostly at night.
Creating an environment that slugs don’t like seems to be a logical and safe solution, but slugs like a moist, shady environment which is what happens when we have a successful and productive garden.
Slugs can be picked off by hand at night when they are feeding or during the day if you leave boards or cardboard in the garden where they will gather during the day.
Some of our local gardeners have had success controlling slugs with dry diatomaceous earth, wood ashes, coffee grounds, or ground up egg shells. These are placed scattered around the base of plant to make a barrier. Thin strips of copper can also be used as barriers.
Beer or yeast water, placed in a container level with the soil, will attract and drown slugs. I haven’t known anyone who continues this on a long-term basis. This method, however, has the benefit of seeing our success every morning.
I have neighbors who lost all of their slugs after snakes started gathering in their compost pile to enjoy the heat produced by rotting plants. Our red-bellied and garter snakes are known to eat slugs as a major part of their diet. Toads, fire-fly larvae, and many birds also like to eat slugs.
My current solution is an iron phosphate compound with bait. This inorganic compound is approved by organic gardening organizations and is safe for humans, pets and wildlife. Metaldehyde and copper compounds can also be effective. These can be found in our local greenhouses and garden centers.
“Mention of a pesticide or use of a pesticide label is for educational purposes only. Always follow the pesticide label directions attached to the pesticide container you are using. Remember, the label is the law. Be sure that the fruit/vegetable you wish to treat is listed on the label of the pesticide you intend to use. Also be sure to observe the number of days between pesticide application and when you can harvest your crop,” University of Minnesota Extension.
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