This post about slugs is partly about trying to stop them demolishing my garden two years running, but first may I say slugs are beautiful. Second, may I say nothing my neighbors or I tried to get rid of them worked. Third, I’ll share a link below to the wonderful series by European master gardener Alexander Boekmann who studied the problem of slugs in gardens for years and years, found what did not work and why, and through diligence and right thinking, came up with a solution.
Part 1: Beautiful animals. Evolved from aquatic snails, slugs live in wet places like our rain forest. Breathing through a hole in one side into a single lung, they see the world through a pair of ocular tentacles that they can regrow if they’re damaged. Gliding through the forest on wavelike contractions of their muscular foot, they push slime ahead of themselves to ease the way.
Slugs have slime on the outside, we humans have slime on the inside. Who’s to judge? Slugs navigate around, find each other, retrace their steps back home following trails of slime much like marketing executives in board rooms or lobbyists headed for the legislature.
And sex lives of slugs! They swing if you know what I mean. I wonder when slugs, endowed with both sex parts do 69, does that add up to 138? Think about it. And there’s no question of who’s wet. They both are. They have to be to get to the party. They can mate as male, or female, or as both at the same time. Which they seem to prefer.
Leopard slugs mate upside down hanging from a chord of slime dangling from a tree branch. Try that Cirque du Soleil. Leopard slugs don’t just dangle from a rope for money, they make their own rope for l’amour. And wind themselves around counter clockwise, and then both of them push their penises out the side of their heads. Giant translucent whoppers, too. Extending eventually about as long as they are. Then those wonderful organs wind around counter clockwise as well. Then spread out into a flower…No, you have to see it. Here’s David Attenborough peeping into one of the most beautiful matings in all of nature.
Now, on to getting them out of the garden.
Part 2: Things I wouldn’t use. Things that helped.
Things I wouldn’t consider using in my garden:
Poisoned slug pellets. Dumping poison pellets on soil growing our plants is absurd. You are what you eat. Same goes for your food and so it follows that we are what our food eats. Slug poison sellers claim slug poisons are safe for people or pets. “It’s organic!” Negative reviews for products like Sluggo tell a different story. There are numerous accounts of this stuff ruining gardens by growing white mold all over the garden and pots, and of killing off beneficial animals you want in your garden like earthworms. Slugs come right back. When they do, you may have killed off their predators. So you’re supposed to keep buying the poison to dump on your garden. Couple things they don’t mention: A common slug poison is iron phosphate. “It’s organic!” Well, unbelievably, it turns out inert chemicals added to these poisons are ‘trade secrets’ and are not required to be listed on packages: As noted from Sal in the Statesman Journal (March 13, 2014, ‘Safe’ slug baits not neccssarily so. ) Sal writes:
But, over past few years, there have been reports in the science community of dogs and earthworms being poisoned by baits containing iron phosphate and an unlisted inert ingredient (helps an organism absorb iron) called EDTA. Inert ingredients are not required to be listed on a pesticide label. They usually are considered to be trade secrets.Reported symptoms in dogs of iron phosphate (plus EDTA) poisoning include vomiting, diarrhea and lethargy.Until EDTA is required to be listed as an active ingredient, or EPA changes the U.S. labelling laws to include the listing of all ingredients in pesticides, the public will not be forewarned of all the risks of iron EDTA-containing products.
In addition, phosphate runoff degrades ground water quality.
Nematodes: another supposedly organic solution that doesn’t work, nematodes are unsegmented worms that infiltrate slug bodies and kill them from the inside out. With these, you’re bringing an invasive species into your garden and you don’t know what else they’re going to kill.
Capturing the slugs, driving them far away, then releasing them. Possibly the goofiest idea posed on the internet.
Things that help (or not)
Beer traps: Two thousand years ago, the legendary Viking king Fjoinir sailed for Valhalla by drowning in a vat of mead. Slugs will make their way into beer traps to join Fjoinir. You can knock them back this way but even if you catch hundreds of them in a season, this isn’t going to get rid of them all for several reasons: Slugs are attracted by the smell of beer. This means you’re pulling them in from outside the garden. (if you choose to use beer traps keep them a few yards away from your plants). Also if you don’t empty the dead slugs every day, other slugs will be attracted to the dead ones. Add to that; watch a few videos on the internet where people put a time-lapse camera on a beer trap. Hundreds of slugs come by, some walk in and drown but a lot of them stick their heads in the beer, drink their fill, then stagger away looking for love. With beer traps then, you may be fueling a drunken orgy.
I did an experiment once of putting out three different kinds of beer to see if slugs had a preference for craft beer or cheap stuff. They didn’t. And finally, my friends say slugs make the beer taste funny.
Going out on slug patrol with a head lamp: Some nights I got dozens. Some weeks got hundreds. Didn’t put much of a dent in the population.
Putting copper bands, mulch, eggshells, or sharp things around the pot or raised bed: I’m told copper tape works if the band is at least two inches wide. There are videos of snails and slugs turning around when they encounter copper tape.The problem I see is all the videos are using fresh copper. Once the metal begins to oxidize all bets are off. Mulch and eggshells were no deterrent at all. Sharp stuff is no deterrent to a determined slug or snail. Those sweethearts are able to walk lengthwise down a razor blade.
Electric fence: Another thing that may work in the short term. Typically two wires running in parallel around a pot or raised bed. You have to keep power to it, usually with batteries. You’ll have to do the same with each raised bed or pot. It will fail eventually and end up in the land fill.
Cutting back bushes: Our yard is full of trees and salmon berry bushes which we like because they give the yard depth, plus bees like the early flowers and birds and squirrels like the berries. Slugs like the bushes, too because they have a place to hide out on dry days where it’s cool and damp. They also eat detritus in the leaf litter. Keeping the bushes cut a few meters back from our raised beds reduces the number of slugs in the beds.
Putting in a greenhouse: Typically you’ve got more control over what roams around your plants if the plants are in a greenhouse. I’ve been thinking about a greenhouse for years and so, I guess I can thank the slugs for giving me that gentle slow steady, one footed kick in the pants to make our backyard greenhouse a reality. That will be another post.
And now! something that actually works: Ladies and Gentlemen! meet Alexander Boekmann: Alex’s series on slugs is a gem in the wasteland we call Internet. After many experiments he hit upon an inexpensive slug defense that seems to work. It’s a band of sheet metal, bent out and down at a 45 degree angle around the perimeter of the bed.
Here’s the link: