Got slugs in your garden? Get solutions that actually work (not the same old misinformation)


A photo of AmyThis article is written in two parts. The first part is what I call my Slug Manifesto. If you’re short on time and just need to know what works without needing to know the details of why most of what you read on the internet is false, scroll down to the bottom of the post until you get to the “what works” section.  

 Classic slime damage with the telling slime trails.I live in the Pacific Northwest, on heavily shaded and moist acreage which is prime slug habitat. The slugs out here grow to enormous sizes–five inches or so. I’ve dealt with slugs before when I lived nearby in the city, on a 5,000 square foot postage stamp lot and so I knew that dealing with the problems that they cause could be exceedingly frustrating. But nothing prepared me for the reality of what what was in store for me in attempting to grow food out here in the country. Not only were my plants damaged, but many times the entire planting would be completely wiped out overnight. Everything I tried to do to get rid of them failed. 

A gorgeous lettuce plant eaten down to the ground by a big slug (oh yes I tracked him down!).But I was determined to figure it out. One fall, a couple of years ago, I decided to declare WAR. I would find out exactly what worked and what does not. I did slug experiments in a styrafoam box that we no longer had use for and recorded the experiments with photographs. What I found out was shocking! The absolute truth of the matter is that none of the purported methods that you read about work. Nearly every "cultural" method is a waste of time, money and resources. All of this information that I learned by trial and error was further verified when I took the Master Gardener Course through Oregon State University. Would've been nice to know that before I went to all that work. Oh well! What I did was this: I got a white styrafoam box and about 30 slugs (took me about 5 minutes to find that many). I tested each one of the popular internet methods. Here are my results: 

This slug doesn't seem to care that he is sitting on a bed of copper.Copper: supposedly, copper is supposed to "shock" slugs, and if you place copper in the garden it will repel slugs. In this photograph, I placed some copper "slug" tape on some cardboard and placed a lettuce leaf on it. It didn't take long (like a half hour) before the slug crawled right up onto the copper and started munching away. 

 Slugs found their way around the copper mesh easily enough.In addition, I tested the "copper mesh" strategy. The theory is that if you twist copper mesh around the stem of the plant, it will repel slugs. Unfortunately, as you can see in the photograph, the theory did not hold up to reality. When I published the findings on my website, the seller of the product criticized me for not putting the mesh tighter around the stem of the plant. My rebuttal is this: First, the edges are extremely sharp and having something this tight and sharp around the stem is likely to injure the plant. Second, it is entirely impractical to go out into my garden, where I could likely have a thousand plants, and maintain these little gadgets. My conclusion: copper is a wildly expensive dud.  

Wood ash: The salinity or alkalinity of wood ashes is supposed to repel and or kill slugs. But tell that to the slug in my picture. I had placed slugs on one side, lettuce on the other. The slug quickly crossed the slug line and devoured the lettuce leaf. Another dud. Besides that, the salinity of wood ashes is supposedly damaging to your garden. 

5/7/2013 9:17:13 PM

It's sort of a pain, but I dust with diatomaceous earth when I see evidence of slugs. Warning; DE will kill bees too, so don't use on plants when flowering.

Robin I. Mack
5/4/2013 6:58:27 PM

Well, I'm prone to using Garlic on the soil. I buy cheap garlic powder at any place that sells it cheap enough. I put it into a Shaker/Spice Sprinkler Canister/Jar/Bottle. About 4:30- 5AM I go outside with it full and sprinkle Liberally on the soil top and by a little while they're heaving out of the ground! As daylight is usually there at the time, the birds, especially the Crows come and "Feast" on them; which eliminates the cleanup.

Darlene McConnell
3/2/2013 11:10:32 PM

I have thousands of square feet of gardens in my yard. My only real problem with slugs is with my Zinnias I plant around the deck. They totally emaciate them when they are young. I do put a 4" wide ring of crushed eggshells(I save them all winter), around them. Occasionally I do put cat food cans of beer with a little sugar in it and seem to catch a lot! My best strategy is to go out with my coffee on the deck and bring my salt shaker every morning. I walk around slug hunting and salt them. They turn to mush!

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