Spring, the season of joyous celebration of the emergence of new life, is also the season in which I find myself most sincerely wishing death to some. I want to kill slugs. I am a peaceful animal lover, but I can’t stretch my loving acceptance to cover animals that hurt my plants. Even the cute little squirrels endanger themselves when they go rooting through my hanging begonias, tossing my beautiful plants to the ground just to bury one hazelnut! Kill!
Slugs are easy to deal with, though it takes persistence. I can actually get my hands on slugs (an unpleasant sensation, usually by accident) and kill to my savage heart’s content. The best defense is a good early offense. Get out the slug bait early, before tender shoots have begun to push out of the ground, and reduce the population of overwintering adults as much as you can. It’s a great way to spend those few nice days of February when it is warm enough to feel like playing in the garden, but too early to do much else yet. In about a month the new eggs start hatching baby slugs and it will be time to bait again to get that next generation. Important reminder: slug bait is far more effective when applied to the ground than when sitting unused on a shelf in the garage. I know this from personal experience with the shelf-sitting method.
Here’s a rundown of methods I’ve used through the years and they all work fairly well.
Beer - The old standard of drowning in beer works fine, though it seems a waste of a product I could find a better use for. Use cheap beer; slugs do not have refined tastes. Set it out in a container that is low enough for slugs to slide up into easily, but deep enough to drown them. Make sure the container does not have a sharp upper rim that could discourage them from sliding over it. If you have a weak stomach when it comes to icky-looking stuff, this may not be the method for you, since a bowlful of drowned slugs is a nauseating sight.
Metaldehyde baits - Deadline is my favorite bait, since my pets have never shown an interest in the gooey liquid. It doesn’t look like food the way the pellets or granular types of bait do. However, Corry’s pellets and any other brand metaldehyde pellets or meal work well, too, they’re just a little more likely to attract dogs and birds, who could possibly consume enough to poison them. Be sure to spread it out widely and lightly, not letting it clump in piles, to help avoid accidental poisoning of creatures other than slugs.
Iron phosphate baits - For you who don’t trust your pets’ sense to leave baits alone, there’s Sluggo, which is perfectly pet-safe. It seems to be a slower kill than Deadline, and you don’t usually see the bodies, because they’re able to crawl away and hide before dying. It does a pretty good job, only occasionally permitting survival and recovery.
When putting out bait of any kind, think like a slug, and put it places they’ll go happily to find it. Don’t bother putting it out in the open – nestle it under plants where they feel safe and protected. Put down short pieces of boards or clay saucers in various places near where you have plants you particularly want to protect and put the bait under those. The slugs like to gather under them and by baiting there you can get a whole bunch of them in those concentrated spots. This also helps keep bait from washing away or diluting in rain.
Copper tape – There is no proof that putting copper tape around plants keeps slugs away from them. Slugs will go over the tape to plants they want to eat; they are not much deterred by it. They are not poisoned by it. The theory that they receive an electrical shock from it is not scientifically supported. And even if it did work, it would be about the most difficult and time-consuming form of protection of all those I have listed here.
Brute force - Stabbing with your weed digger or trowel, stomping with your foot, or squashing with a rock are all excellent methods. They are time-consuming, but give the satisfaction that only good vengeance can give.
Tossing slugs into the compost can provided by the garbage company will not do the job, unless it’s only a few minutes until the truck is due to pick it up and empty it. Slugs are quite mobile, even though they seem slow, and can crawl out pretty quickly. I have found slugs on my roof many times – climbing out of a garbage can is no problem for them.
Slug corpses are good compost, just leave them to rejoin the earth. Remember that little graph of the nitrogen cycle in high school biology? No? Well, it shows how all the dead bodies join the soil and get used by plants and then animals eat the plants, etc. Slug corpses are organic fertilizer. Also, live slugs will come to eat dead slugs, so put some more bait around the bodies of the fallen. Wait – can one fall if one is already flat on the ground?
The other terrestrial mollusks some of you may have to deal with are snails. I have heard tales of populations of big snails in Keizer and Woodburn gardens. The California Brown Snail is a quarantined pest. They aren’t supposed to be here in Oregon. All the shipments of plants out of California used to come with a certificate stating they have been inspected and found free of snail infestation. But under-funded inspection programs couldn’t keep up, and now many have made it through the border and are happily reproducing. They can be controlled with the same methods used on slugs, just ramp up the efforts. Be persistent. Re-bait after heavy rainfalls. Put out bait even where you don’t expect them to be. And show no mercy when you encounter them live. They are terribly destructive.