St. Louis Park, Minnesota

If there where a "best" way of controlling slugs there wouldn’t be so many ways. Over the years one has seen scads of articles written on this subject, many of them very imaginative. This summer I heard of more new schemes than ever before. Perhaps this is because I had significant problems with these unspeakable pests and was looking for alternatives to failed strategies. When my current system didn’t appear to be permanently eliminating the slugs I looked for a new method-and there where many to choose from.

There are the two standard techniques: beer and Bug-geta (or some other protein-baited methaldehyde compound). The beer is placed in a shallow receptacle and the slugs are attracted to the odor of the malt )or hops or whatever it is that slugs like) and once inside the slippery-edged container they drown. My neighbor and I tried this "politically correct" means of dealing with the hated gastropods. Initially, he had far better luck which I attributed to having a better bait-he used Bud Regular and I was using Bud Lite. When we went to check the bait traps he had half a dozen dead slugs while I had half that many. So I switched to Heineken’s and the race became more even. However, he then put his bait station close to his compost bin and they must have been breeding like rabbits in there because he again claimed a larger body count. The bait used and the placement seem to be the key factors with beer and traps. The traps themselves are of lesser importance. On the market are a lot of different styles of upscale containers in which to place the beer, and you are charged accordingly. Usually the pricey ones have clever tops (I guess to keep rain out of the beer) and cute names such as "Slug Pub", although I prefer blue-collar names like "The Terminator" or "Pit of Death."

Beer wasn't the answer. The slugs would still eat the hostas; we could only hope to keep the numbers down by knocking of the ones with serious drinking problems. Still, environmentally safe methods have a certain appeal and I was anxious to try them before resorting to poison. Walter and Jean Rideout from Madison, Wisconsin, are gentle, nature-loving folks. They shared their slug secrets with me. They, too, disparage the use of chemicals; so the good doctor and his wife don caps with flashlights attached (like miner's hats) and go into the garden at night armed with 'Dust Buster' hand-held vacuum cleaners. Zzlaat! Zzlaat! They suck up each slug they see with the vacuum. The neighbors thought this activity bizarre at first, but after a while accepted it as part and parcel of the Rideouts' eclectic philosophy and interests. The Rideouts said it was fairly effective, but I didn't think my wife and neighbors would speak so kindly of me (and also, I didn't want to fight mosquitoes and raccoons in the dark) so I eschewed the vacuum.

Next I went to a fairly new and fascinating concept-copper barriers. Brian Flannery from northern California (where they have real slug problems) once told me how the farmers raising avocados and lemons would place a narrow band of copper around the trunk of the trees. Apparently slugs get a shock or something when their slime trail contacts the copper. Whatever the reason the slugs wouldn't crawl over the metal strip and the farmers could protect their trees this way. San Francisco's Art Santmier placed strips of copper screen around the edge of his potted hostas and virtually eliminated slug damage. I was a little reluctant to use this system because last year my roofer told me how I could prevent moss from growing on (and damaging) my cedar shingle roof by putting strips of copper down every few feet. Also Herb Benedict mentioned that he had killed all the goldfish in a small pond one year by placing a copper screen over it, inadvertently allowing the rainwater to carry small quantities of copper into the water. It seemed that if it would kill moss and fish it might be pretty hard on hostas, too.

Reliable expert information was needed. I called the department of plant pathology at the renowned University of Minnesota School of Agriculture. They didn't have a clue as to whether it would be harmful to hostas or any other horticultural material, but it wouldn't lay a glove on alfalfa they said. The supreme guru of horticulture problems in Minnesota is Deb Brown, Director of the State Horticultural Society. The department of plant pathology, which by now was interested in this, had her call me to discuss it. She didn't know either, but encouraged me to try it on a few replaceable plants and let her know at the end of the season. Good advice.

I got hold of one hundred fifty foot strip of one-inch-wide copper and started cutting into twenty-four to thirty-six inch lengths to place around the bases of the plants like a clown's collar. It was very easy to work with and could be crimped to close the loop with no difficulty (forming triangles and other polygons was easier than trying to make circles). Two sizes of strips where adequate for almost all the plants regardless of their size (with the exception of the very smallest). I placed collard around those with the earliest and most severe slug damage while leaving their neighbors unprotected. Because it proved almost impossible to tell new damage from old I cut all the injured leaves from many of the copper-protected plants so that any observed leaf damage would have to be "new". I didn't do it for all the protected plants because some of them had only a few leaves and so many small it would virtually devastate the plant, and it didn't seem to be necessary to study all the hostas. The neighboring hostas were given periodic treatment and/or protection with various and sundry techniques-whatever I was doing at the time. The copper-protected hostas did much better than any of there neighbors. The most dramatic case was that of 'Peppermint Cream'. It was the first to be hit by the slugs and there were a half dozen leaves with serious holes in them. Meanwhile, it's next door neighbors 'White Christmas' (usually as sensitive as a canary in a coal mine when it comes to detecting slugs) was unblemished. Needless to say as the season went on not another mark appeared on 'Peppermint Cream' while 'White Christmas' was riddled by marauding mollusks-as were it's neighbors 'Iwa' and 'Torchlight'. 'Iwa' and 'Torchlight' were ravaged until they got their copper collars. The carnage continued with 'White Christmas' despite Bug-geta, imported beer, search and destroy missions where each morning I would turn over rocks and flower pots looking for slugs to crush with stones, and importing toads (the toads never seemed to want to stay). The only thing that stopped them from the rapine of my 'White Christmas' was the chemical measurol. That was effective!

Most of the usual chemicals were only slightly effective in the big outbreak occurring at my place this year. The epidemic may have been as a result of adding huge amounts of compost to each plant in early spring-as any competetive gardener would do to get bigger and better plants than any one else. A warm wet May and being out of town, thus leaving the garden unprotected for a week or more at crucial times when the slugs are actively mating and laying eggs were additional factors.

At the Great Lakes Regional "Hosta College", Clarence Owens, the biology teacher from Michigan, covered the topic of slugs in his course on Garden Denizens. He scoffed at trying to control a serious outbreak of slugs with the commercially available chemicals, but he said a substance called measurol did work. Unfortunately, measurol has been taken off the market. It is available for use if you are raising ginseng root. Apparently even the EPA is overruled by the purveyors of performance enhancers. So if you want to get some serious slug poison you need to know someone with serious ginseng root contacts. I did.

Axel Troedsson showed up at my place one day with a small plastic bag full of the stuff that looked like dry dog food, only it was white. He said it was what I needed to clean up those ugly holes in your hostas." He put on some rubber gloves and went around the yard like Johnny Appleseed scattering this white stuff under plants and next to flat stones and near drainpipes-about a dozen spots in all. Before he left he said, "If this stuff doesn't work we'll use pulped Lutefisk."

When I came home from work the next evening I went to see if anything had happened. Had it ever! Wow! There were dead slugs everywhere-twenty or more by many of the piles. Those slugs hadn't moved more than an inch after coming into contact with this white stuff. It was lethal.

Then I started to worry. There were several dead angleworms and a sow bug or two that hadn't moved more than an inch after hitting the white crumbly bait, either. I called Axel and had him read me the label over the phone. It was measurol all right, but only a 2% concoction. The antidote Was atropine! That's the stuff they were issuing to the troops in Desert Storm that were going to be exposed to Iraqi nerve gas. I called some people I knew at the Poison Control Center. Measurol is an organophospate, they said, just like the nerve gas. But it isn't nearly so lethal and in a 2% mixture it isn't the worst stuff you could think of. They said anyone using it would need gloves and should be Quite careful, but it will break down after a good rain or two and won't build up in the soil. The human risk isn't the problem; it's concern about birds and fish in the "run-off" area. If people were to use it in broadcast fashion it could cause a serious environmental hazard.

After two treatments with the measurol it seemed to end the epidemic. Several of the plants sent up a new flush of leaves that remained almost untouched the rest of the summer without further treatments with anything. And copper collars didn't seem to cause any harm to the plants they were protecting. So I guess it worked out okay. I only wish I had been a little more scientific about how I had used these various treatments.

I talked with a number of people about slugs this summer and many told of controlling them with unusual methods. Frank Greer, the pediatrician-plantsman-scientist, from Madison, Wisconsin, tells of visiting a vegetable garden in the midst of a slug devastated community in Vancouver. It was spared thanks to a herd of vigilant geese that was kept penned with it. The birds literally had slime oozing from their bills and flowing down their faces and necks form the scores of slugs they would nail on the dead run while patrolling the perimeters of the fenced plot. Perhaps this is not what you'd want in your yard, but the method appears to be extremely efficient.

This bird patrol concept must be the rage on the West Coast. Charlie Purdyman and Jay Hyslop, the people at Walden West, told me how for a while they were trying bantam roosters to monitor the rows between their lined out hostas. They were almost as good as the geese and easier to handle. But Purdyman couldn't stand having them under foot all the time and they eventually divided the garden into a traditional side (Charlie's) and Jay's fowl free-fire-zone. They've given up on the chickens now-too much collateral damage- and are back to where they started.

Robyn Duback, another west coast slug sufferer (but not one to suffer indignities silently) shows the giant Pacific slugs no mercy. At the 1993 AHS Convention in Iowa City she told a mesmerized hosta klatch tall tales of mammoth banana slugs attacking her garden. Even the stoutest of the gardeners were taken aback as she recounted the lurid details of how you need to treat the slugs like vampires if you want to keep them away. Robyn captures them by night and leaves them out in the midday sun with wooden stakes driven through their bodies. "That finishes 'en off," she counsels.

Meanwhile more genteel methods are used in the Midwest. The prime example is softhearted Russ O'Harra who uses toads which neighborhood children bring him. He even went so far as to build a little house for them near a water pool-sort of a toad hotel-hoping to make them content and willing to stay.

Dr. Jim Wilkens, the star of Victory Garden, uses a newspaper (he says the Wall Street Journal works well) folded in half and soaked in a bucket of water. He puts it down in the garden at night, picks it up in the morning looks for slugs on the underside. Then he crushes them with a hemostat. (He seemed like such a gentle man.)

Larry Clemmons, an accomplished hosta grower from Dubuque, had an almost slug-free gorgeous garden last year while many of his friends from nearby towns were being overrun. Unlike the beer and lightweight chemicals they were using, Larry was spraying the hosta once a week or so with a dilute solution of plain old ammonia. The slugs hate the ammonia and the plants love the nitrogen. He uses a regular inexpensive tank and nozzle sprayer and went over and down into each plant-and he has a lot of them. He sprays the hostas with a dilute (4:1 or even weaker) solution of water and household ammonia in the evening once a week-more often in the spring or with a lot of rain. It would take him no more than two hours a week and there were almost no slug holes. The folks visiting from Iowa City which was being inundated by mollusks were astounded by his lush foliage just a few miles away and many have adopted his system.

Perhaps the most interesting new approach was mentioned by Warren Pollock at the Winter Scientific Meeting in Chicago. He reported that he had it on "good authority" (he read it in The Times) that enterprising people in Great Briton have found a slug-eating nematode which doesn't harm plants. Test are being run to see if it will be better than the current means of handling slugs. Some of the tests are being conducted at the University of Minnesota Arboretum, but there entire Hosta Glade was hit heavily by hail earlier this year and I wonder how they will be able to gather good data. Nonetheless, the "battle of the worms" has a good ring to it-I hope it works out.

So, as you can see there is a lot of action in the war on slugs and perhaps in a few years we will have a single "best method" for dealing with them. More likely, we'll have a number of systems to hold the slugs down (ammonia, flesh-eating nematodes, armies of toads and copper barriers, etc.) and some reliable/safe chemicals to use in a crisis-or better yet, breed slug-resistant hostas. But until then we continue to learn a lot about ourselves and our innovative and imaginative friends who must be thinking of slugs constantly to come up with these bizarre and wacky (and successful) ideas.

 Information on joining the American Hosta Society and its regional and local societies can be obtained from the AHS.

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