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Nov 07, 2010

Here in the Pacific Northwest, slugs are the biggest problems for us home gardeners. I can go out at night and there will be countless slugs, up to 4 or 5 inches in length. They eat their body weight daily and can cause absolute devastation in the garden. 


As a person who is attempting to rely on my vegetable garden, this is a huge problem. I'm on a mission to find out exactly what popular methods work here (most do not) and what products are worth the money (most are not). I'm conducting detailed experiments on my personal blog with photographs. 


My latest blog entry is a discussion on the expense of iron phosphate


If you have a slug problem, share your stories with me! I can commiserate. 


Amy, I have had slug killing success with 2 things that I have around the house. I have taken a shallow container and filled it with beer dregs (you know, the swill left over in the bottom of bottles in your recycling bin). Then I bury the continer part way in the ground in the garden. After a couple of days I have a container of dead slugs. I'm not sure what kills them, but I like to think that they died in a happy stupor. Also I have found that crushing up eggshells and spreading them at the base of plents keep the slugs off. As a bonus, some calcium inevitable makes it back into your soil. Again, not sure why this works, but my neighbor suggested it to me and she was absolutely on track. I also often employ the manual squishing technique as my son thinks it is super funny. I tell you this with the caveat that I live in the southwest, so deal with fewer slugs overall due to the relative moisture level. PS I like your blog. -Johanna
Thanks for the suggestions Johanna! Unfortunately, I did an experiment with the crushed eggshells and photographed the slugs crossing eggshells with no problem whatsoever. Also, the beer traps appear to work, but, if you check out the photos on my experiment, you will see that not all slugs will drown. In fact, many slugs take a big drink of beer and then move on. So, in effect, beer kills some but feeds others! At the very least, I would not bother buying beer just for that purpose. I think any money would be better spent on iron phosphate or fertilizers to help plants grow faster (because plants are most vulnerable when they're young). Thanks for writing and your suggestions!-Amy
Amy, Yikes. Your slugs are enormous. It must be that humid climate. Maybe ours are dehydrated here and the beer hits them a little harder. Who knows? Do your slugs have any natural pests? I feel like some of the birds in around our yard eat some of the slugs also. I sympathize with your slug battle. I had a similar fight with cutworms this summer but was able to outsmart then this year with a combination of methods... but I digress, it is off the topic. Keep fighting the slug fight. -Johanna
Hey Johanna, somehow I missed the response to this post. Sorry! Anyway, I wanted to let you know that I had a horrible cutworm problem once too. It is not a well know pest here in the Pacific Northwest. I made a big mistake one year of doing sheetmulching with enormous amounts of leaves. Unfortunately leaves don't break down well here, and allows bugs to proliferate like mad. These cutworms were a little unusual in that they actually climbed the plants and ate, just like slugs do. Not only that, but they went after the plants that slugs normally leave alone, such as garlic. I had to go out at night and snip them all in half with scissors, use BT, and rake up all my leaves (enormous task). Eventually I got them under control. How about you?
Amy, We used cutworm collars and row cover over the entire garden box (see below). Also, I went our and used a hand rake every few days around the plants and this seemed to bring some of the offenders to the surface. (I squished them at this point). This worked pretty well. I'm kind of a geek for low tech methods that require trial and error, I work in the sciences so I guess it comes with the territory. -Johanna
I have not had cutworm problems, in my raised beds. But I have gardener friends who have used both of your low tech methods to stop the cut worms. I wonder if the coffee chaff stops the cutworms or if they just have not found my garden yet.
You have to bury the container( yogart cup) & fill it about 2/3 full, to drown the slugs. When it is done right it can kill as many as 100 slugs in a month or so. Egg shell need to be toasted in the oven & broken up the expose the many sharp edges. I use them mainly as composting around plants. I use tea & coffee grounds, coffee chaff to keep them away. The caffine is toxic to slugs & snails. But as we say on the "Garden Pest" group, the best way to stop slugs is to keep your garden clean. A clean orderly garden leave little room for slug nest. Boards,dog or cat food is another way to draw the slugs in, but traps should be cheched daily.
Yup, those are official northwestern mega-slugs you have there. Honestly, I think ducks might be your best answer, but if that's not an option, I think you need deeper containers. Most of our slugs are only an inch long, though occasionally we will spot a big-un - two inches long! ;-) We use tunafish cans, fill them nearly to the top, and bury them so that the tops are even with the soil. We use budweiser, because it just feels right :) And we read somewhere that a study was done and that was the favorite. It seems to work. For your slugs, maybe large yogurt tubs or bean cans, only filled an inch or three at the bottom. If that doesn't do it, for an extreme trap, punch holes in the sides to create spiky flanges pointing down, so that even if they go in for a drink and then fee like leaving, they won't be able to get purchase on the sides, increasing the chance of dealing death. If it works, check the traps at least every other day - after they die, they dissolve, and after they dissolve, they stink. Badly. The amount of putrescene put out by a week-old slug corpse is impressive. Ducks. Go with the ducks.
Thanks for your comments. I think the slugs are just too big and strong here for the beer method to work very well. Besides, beer is expensive! I'm trying now to use bait most effectively (environmentally and pet friendly bait, that is). I'm curious to see if I keep the gardens very well baited throughout the fall, winter spring, if that will eliminate the slug population. After that, heavily maintain the perimeters of the gardens with slug bait and be careful to watch for any slug damage throughout the gardens. Perhaps that will work!
I have long beds on my allotment. They are 4 to 41/2 feet wide by about thirty feet long. I do not like to step directly onto the soil, so to make diagonal progress accross the garden i employ stepover boards at points along the beds. At this point you are wondering what this idiot is rambling on about when the subject is slugs. Well the boards also serve another function, in that they attract slugs that normally live within the soil, to live on the underside of the boards. If the boards are turned over at regular intervals then the now visible slugs can be despatched in any manner that you feel appropriate. I have no qualms about it, i step on the little buggers. Glenn
I grew up in Oregon, so I know what you mean about lots of slugs. These comments are priceless - so useful! The use of eggshells is great recycling. We don't have slugs here, but I broadcast eggshells directly on the garden beds after giving them a spin in a blender or food-processor. How about Ducks? On a 3-month visit to my natal family, I spent the earliest daylight hours in a rose garden overlooking the Pacific - deadheading the roses, stashing the petals to dry, pruning/reshaping the bushes from the ravages of quick bouquet-cutting & collecting a full bucket of snails that were still at large in the hilltop xeriscape groundcover plantings. I had adopted the ~dozen ducks in a wire enclosure down in the Avocado orchard & they loved a bucket of snails thrown over the wire fence! Then they loved it even more when we started letting them out daily to graze the hilltop directly. You could hardly herd them back in but in late afternoon they returned to their enclosure promptly before the coyotes started talking to each other about what's on the menu tonight! In a viewline from the main house, we put a medium sized child's wading pool under a big overhanging tree/bush so the hawks overhead couldn't see them & they rested there during the day. Library research said ducks need enough fresh water to immerse their heads & eyes frequently. Also, that ducks are much more cold & wet-hardy to keep than chickens. Duck eggs are popular - certainly in China! - and their flavor may be influenced by their diet, like your goats' milk, Amy. These ducks ate minimal bagged duck-food, snails & ? forage. We did eat some duck eggs & the taste was "good eggs." The watch-bird peacocks had to be screened from the various edible plantings I made - they are hard-wired to eat green seedlings - but the ducks were attracted to other fare. You may be living in duck heaven! I feel sure that ducks would forage on your slugs, either by the bucket or directly.
Hi Amy It is possible to obtain a nematode slug killer that you mix with water and sprinkle onto the plants. I am led to understand that these kill the slugs in a totally biological manner. In the UK it is sold as 'Nemasys' I have not tried it because it is quite expensive. If your slug problem is as bad as you say then it may be worth investigating this product to see if something similar is available in your area. Regards Glenn
I tried where I have gotten a nematode fungus gnat killer process for my Garden Hallway - which was totally effective. Of course there the fungus gnats hatched only annually from an addition of peat moss. Slugs are perpetual, it sounds like. Gardens Alive's one listed slug killer comes full circle to Amy’s post & looks expensive. Even inexpensive would add up with the perpetual slug population she describes & so garden productivity calls for a systems-thinking solution using natural systems. TBD! “Escar-Go!(R) is a unique blend of an iron phosphate active ingredient, originating from soil with slug and snail bait additives. It is used as an ingredient in fertilizers. The Escar-Go!(R) that is not ingested by snails and slugs will degrade and become a part of the soil.” Escar-Go! 5.5lb treats 5500 sq ft @ $29.95” Maybe it’s time to tell Gardens Alive about nematode slug killer & see what they brew up. It sounds like there would be a huge market & that's a big incentive to development & a volume market helps keep prices down.
But from what I understand: -they will only populate on soil that is relatively warm (the soil is really only warm from late spring to very early fall) -the nematodes you purchase have to be very very fresh, or it is likely they aren't alive (I think I read that in Steve Solomon's book) At any rate, it is something I have on my list to look into a little further, as I would like to know everything I can about getting rid of them.
- but all too seldom seen - so thanks again for the way you document your experiments. "Relatively" is a category for experimentation. Nematodes persisted in my Garden Hallway in winter with no heat except passive solar & two dog beds. I'd have to look back in my notes to see what soil temps were during winter growing, which felt like Oregon winters. You never know until you try with some things. Red worms are said not to be cold-hardy but mine thrived & increased through zone 4 winters in two meter-square connected compost bins. Dead of winter is 20 degrees above to below zero here, or colder. My fungus gnat nematodes arrived from Gardens Alive as a dry sponge about 2" x 4" X 1/4." You soaked it in a few gallons of water for a few hours & then "innoculated" the garden beds by sprinkling. It felt like someone was playing a joke - but worked.
It is worth a shot. I'll post about it when I try nematodes.
The best long-term solution might be a combination of those we've discussed today. Some methods cost more up front but less over time with a recurring need - such as controlling slug damage to gardens. And back to Ducks - they add value & fun.

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