slug control, with a little help from my friends

slugT HE BEST REMEDY FOR SLUGS WAS AN END TO THE RECENT RAIN, after 13 or so inches the previous 30 days. But though the drier weather slows them, I am left with a bumper crop of the shell-less mollusks with their voracious hunger and telltales trails of slime. What’s a gardener to do?

eaten-abutilon-leavesKnow their habits: Slugs do most of their damage by feeding in evenings and early mornings; they like moist, secretive places better than a place in the sun. Their favorite fodder is often the youngest and most tender seedlings, but they (and their shelled cousins the snails) will eat molds and decaying material and even leathery things like orchid leaves (below), too, not just my Abutilon (above) and hostas. Nothing is safe: foliage, flowers, fruit, and even some seeds are fair game.

eaten-orchid-leafDon’t water late in the day, which will only encourage bad behavior, making things moister during play time.

Eliminate hiding places. Wilted or slightly decaying foliage left in the garden can provide perfect hiding places, as it often bends to touch the ground. This week, now that things have dried a bit so I can get into the beds, a more ruthless approach to cutbacks than normal is scheduled, since the extreme rains caused so much excess, often floppy, growth.

Don’t over-mulch. One to perhaps 2½ inches of mulch is desirable; layering on thicker amounts than about 3 inches just invites damp conditions that slugs love, plus it provides a great place to hide.

Set out safe baits or traps. There are self-described “nontoxic” slug baits these days (though research institutions like Cornell use the term “low-toxicity,” which is probably more accurate), like Escar-Go! and Sluggo, based on iron-phosphate formulations. I have never used any, so am without any detail or endorsement to offer. I’m still back in the lay-down-a-board or sink-a-can-of-beer (as in tuna can or shallow plastic deli container) school; half-grapefruit rinds work, too. Seriously, pieces of discarded lumber laid down in areas of heavy infestation and upturned the next morning will yield lots of hiding beasts that can be scraped into a bucket of soapy water.

Other barriers, like copper strips (are you kidding? I would need 20 miles of this) or Diatomaceous earth (not the kind rated for use in pool filters, but the untreated kind for garden use) are also said to be effective, but the latter is scary-dusty (wear a mask) and needs to be reapplied after each rain (again, are you kidding?). My scraps of siding and shingles and trim don’t mind being rained on, and have weathered many years.

garter snakeEncourage snakes. Many species (including garter snakes) eat slugs. So do salamanders. Walk your property (with a heavy foot!) before firing up the mower, as snakes can’t really hear it and get away in time otherwise. It’s vibrations that signal them to get going, apparently, and avoid being hurt by the machine.

Be brutal. (Take anti-nausea drugs before attempting, as needed, tee hee.) Hand-pick and squash as many as you can, or drown them. A friend who’s somewhat slug-intolerant, even slugicidal, snips them in half with shears. Effective, if brutal. Salt works as well, but at this point I’d need a shaker the size of silo and I could be on patrol with it many hours each day. Trapping (think: beer and boards) is more time-effective.

male-green-frog-mating-seasonLove a frog. Or a whole army of them (yes, the correct word for a group of frogs is army). That’s what I am after: an army of frogs. But you already knew of that proclivity of mine.

86 comments
July 6, 2009

comments

  1. says

    Oh, Margaret, such a timely post as I accidentally killed my garter snake while mowing this morning. We had an agreement that he would remain unseen when I was in the garden, but the other hours of the day he had free reign. And now all of his free pest-control is gone. I am sick.

    I did not realize they could not hear. I’ll keep this in mind next time.

  2. says

    HI Margaret: Sluggo works well, don’t need a heavy application. Be careful there is a Sluggo Plus that contains
    spinosad so its a little more broad spectrum.

    We used handpicking, beer traps and finally sluggo to impede the invasion.

    Thanks for the tip about snakes not being able to hear.

    Have a great Evening
    John

  3. Brian G. says

    Salt shakers and snipping them in half with shears? Eek, Morticia Adams would be proud.
    When I got home at about 11pm Thursday night there were 7 or 8 slugs on my front door not counting the ones loitering on the front steps. I still can’t figure that one out. Attempted burglary?

    • says

      @All: Re: the sense of hearing in snakes is very interesting, and apparently is connected to their jaw and vibrations felt there (since the don’t have an outer ear). This Scientific American article is worth a browse (or you can listen to the longer podcast, since you have ears). The more thorough version, from the Discovery Channel, is here.

      Anyhow, when I said somewhat imprecisely that they cannot hear the mower, I mean they can’t sense or “hear” it until it’s too late to respond to the fast-approaching vibrations and get out of the way.

      Snakes’ senses are all quite different from our normal human concept: they smell with their tongues, I think (which is why they flick them, to collect sensory data), and in the case of pit vipers (like rattlers) they have those “pits” on their heads that sense heat (and therefore their prey). Fascinating. I really am trying to embrace the snake world here, and stop running shrieking across the yard, you know. :)

  4. ruth anderson says

    do slugs eat away at iris’ or day lily leaves, something is sliming away or eating away on them and leaving white stipes, as though eating the green off and all you see is white as if some took a knive or object and stripped away, does anyone have a clue i am in south carolina,lots rain prev but dry now,,,

  5. says

    I use sluggo, but put it underneath boards or overturned tuna cans, leaving a small gap so the slugs will find the bait. I have not had too much trouble with slugs and snails since using it.

  6. says

    We’ve had a ton of rain lately, and the slugs are out in force — bad for my plants and the ick factor of my 4 year old (daughter no less!) trying to carry them into my house!

    She caught me giving them a “salt bath” but is still trying to pick up the remains…I’ll have to remember these tips for preventing the buggers!

  7. says

    Welcome, Ruth. Slugs can eat both, and the edges of the eaten spots would be somewhat jagged, because of the way slugs eat, and you’d probably see slime trails. There are some viral diseases transmitted by thrips that can cause stripes of discoloration, as if the green’s been taken out, as well (some of my onions, which are susceptible as are irises, have it here in this oddball weather year we are having I fear). Tried to find a photo that showed what it would look like. Try this one or maybe this one. Viruses like this can also be transmitted to daylilies (photos here). What do you think?

    Welcome, Going Green Mama. Your daughter is very brave, and is obviously going to be a fierce gardener! No pests will be left to eat her plants. Send her over. Nice to see you, and hope to again soon.

  8. chigal says

    Ugh! That’s one pest I haven’t had to deal with. I think I’d use the slugs as an excuse to get a pet duck.

    Do you remove/compost mulch when it gets too thick, or till it into the soil? I’ve been mixing it in, and I wonder if that might be a bad thing for plant roots, as it isn’t fully broken down at that point. I use bark and pine needles.

  9. says

    I have been waging war in our north Florida garden for two years. they ate everything last year. This year, I am actively using beer traps but they also need changed everyday and frankly, the presence of pursulane in the garden has really worsened the problem, though the pursulane is slug tolerent so far…

    Finally, I threw up my hands, went out and weeded the front lawn of all the pursulane and transplanted it everywhere. I am so over this fight. Dirtbags.

  10. says

    Haven’t had slug problems (knock on wood) but have plenty of snails. Hate them. I have had to break out the Sluggo when there were SO MANY but mainly hand pick and squash. It’s therapy. As we are warmer here, I find I just cannot mulch some areas or I have a snail farm. Thanks for all the tips.

  11. dawn says

    Umm, yes, this is a subject with which i’m intimately familiar. I had a beautiful, lush, vibrant crop of potato plants growing, that is, until our 3 weeks of daily rain. It is the nature of growing potato that you are supposed to “mound” them with mulch as they grow to give the tubers underground a space to grow and prevent geen spots ont he tubers caused by exposure to su nlight. So, I mulched.

    I handpicked slugs off my plants every night for weeks, picking off as many as 146 in a single night butmost times getting somewhere between 40 and 70. I collect them then throw them in a sewer to drown. Their orange slime is difficult to wash off, but a dry tissue/towel does the job.

    I’m wondering if my potato plants will produce any ptoatos after being so ravaged. They haven’t bloomed yet. Is there any hope?

    PS I tried the diatomaceous earth and found a number of slugs crossing it (!) so i question its effectiveness now.

    What really worked is, as you said, it simply stopped raining.

  12. says

    @Chigal: My mulch, a fairly fine-textured composted stable bedding (sort of wood shaving to tiny chips, that horses/cows have used in their stalls, and was then piled up and composted *before* I use it as mulch), breaks down into the soil through the months. That’s what makes this material ideal for mulch: it’s pre-composted, and you can never really overdo it, because it works in by itself gradually.

    Welcome to the Blushing Hostess. “Dirtbags,” you say? Yes, exactly. Or more precisely, “Slimeballs.” See you soon again, and keep up the good fight. We are rooting for you (and against them).

    @Dawn: Depends on the damage. The plants need to photosynthesize through ample foliage to store up reserves in the tubers. That said, potatoes grow pretty lustily here…so they may grow enough green to feed themselves. I don’t know how serious a situation we are talking about?

  13. Julia Thiele says

    So, finally some sun, but not much. Finally some warmth, but not much. Four tomato plants have rotted. Marigolds sit low to the ground with closed up buds. The Hollyhock reaches up but finds no sun and has no buds. The lavender is dull. I add topsoil. It does no good. I praise and cajole. They put their soggy leaves over their buds. ‘Please, Sun, come out and make her stop talking!’

    Walking to the boat, I found four horseshoe crabs on their backs on the sand. I jumped off the dock, in the rain, picked them up with their legs wriggling crazily and their pointer gesturing wildly, and creeping me out in the process, and put them back in the water. Oh, what a good deed did I! The next day, they were back again, on their backs in the sand. Is this where they want to be? Have they come up here to lay their eggs?

    I said, ‘you know guys, you’ve been doing this for a lot of centuries. Perhaps you don’t need me to carry you, flailing, back to the water so you have to wait out another tide in order to get back to the dry sand. Perhaps you’d like it if I just turned you over and went away.’ I did, they heaved a prehistoric sigh of relief, and scuttled awkardly into some egg laying position only they can understand and, frankly, only they need to! I left. The eggs will hatch or not, and horseshoe crabs will go on. The marigolds will bloom or not, and gardens will flourish again. Tomatoes will grow and be plentiful or not, and children will pluck them off the vine and eat them warm from the sun.

    They do not need me. I need them.

    • says

      Welcome, Julia. The forces here try to silence me as well, the plants with leaves over their “ears,” the frogs, the snakes, the birds, even the cat. And yes, the cycle will repeat some version of itself with or without our intervention. Thanks for your great comment. See you soon again.

  14. Deirdre says

    Because of our mild winters in the maritime NW, slugs start early. I begin putting out iron based slug bait as soon as the bulbs start coming up. That’s in February. It also helps catch them before they start reproducing in the spring.

  15. says

    We stomp on them here, but then we also get the really big banana slugs that can mow down a stand of lettuce in no time! If left to rampage thru the garden, they will also crawl into the greenhouse and leave their slimy trail on the sides.

  16. rose says

    This morning when I went out to check and empty my cans of beer, I found an unexpected bonus: dead earwigs!! Apparently they like beer too. This is good news for me. I am currently suffering through an earwig infestation of epic proportions and boy, can those kids eat.

  17. says

    Oh, my, Deirdre…so early! And on, my, Janice…so supersize! Ugh on both counts.

    @Rose: Brilliant of you to share that earwigs are lushes and drowned at the party last night, too. This is great news. Congratulations.

  18. Rosemary says

    I FOUND PUTTING USED COFFEE GROUNDS AROUND PLANTS KEEPS SLUGS AWAY. I DON’T KNOW IF THEY DON’T LIKE THE FEEL OF THEM WHEN THEY CRAWL OVER THEM, BUT IT WORKS FOR ME. I ALSO SPRINKLED SALT ON THEM WHEN I SEE THEM.

    • says

      Welcome, Rosemary. Yes, coffee grounds are said to be a slug-proofing tactic, and I have read that it’s because of the caffeine (which permeates their bodies and kills them, some references say) or the texture (but I have seen them crawl across much coarser stuff). An article on coffee in the garden from the Seattle paper a few years back, fyi (the slug part is pretty far down, and echoes what I have read in various other places). See you soon again.

  19. says

    Out of necessity, I developed a rather unusual method for dealing with the overabundance of slugs in my central CT gardens. I fill a can or other 2-quart container about a third of the way with water, add a squirt or two of liquid dishwashing detergent, and grab a plastic spoon. Then when ever I see a slug I scoop it up with the spoon and deposit it into the soapy water. I give a full account of this process on my blog, http://www.joenesgarden.com. So far, my slug problem has diminished significantly.

  20. says

    Welcome, Joene. I love the plastic spoon idea; touching these guys really makes me ill. Thanks for the tip, and hope to see you soon again.

  21. says

    The slugs seem to love my guacamole hostas. Coffee grounds didn’t work at controlling them. I haven’t tried the beer solution yet, just because I don’t have any in the house and need to go get some. So I’ve tried the board method you suggested. We’ll see what happens.

    • says

      Welcome, Cheryl; if you lay down the boards and then check them in the morning, I think you’ll find some unwanted individuals lurking, and the beer definitely works. (Get them the cheap stuff, tee hee, nothing special.) See you soon again, I hope, with reports of a diminishing population.

  22. says

    I have been sprinkling Sluggo about once a week, with good results. I grow a lot of lettuce, and unfortunately I am very squeamish about eating anything a slug has even looked sideways at.

    • says

      Welcome, Logan. Yes, nothing like “extra-crunchy” lettuce, ugh. Especially after 30-plus years of vegetarianism here, a horrible experience. I hope to see you again soon (perhaps on a more upbeat topic, sorry). :)

  23. says

    Need to add my two cents. Not for the queasy but this really works. Get a nice sharp scissors, take a little stroll around your garden in the evening when the slugs start to emerge for feasting, snip the big slugs in half with your scissors…making sure they are at the edge of a bed – so you can see them clearly. The next morning, early if possible…go for a little stroll to the snipping sites with a cheap spray bottle filled with plain amonia – the snipped slugs will have attracted a bevy of live slugs…give the whole bunch a little spritz of amonia – I like using amonia over salt because it doesn’t leave a dead spot on the lawn or ground covers like salt does. I know it’s a bit creepy but when I think of all of the plants the little monsters have destroyed I get over it!

    • says

      Welcome, Shelly. My friend snips them in half, too. Didn’t know bodies were a lure. Ugh, but interesting. Hmmm….ammonia…now you have me reading old Reader’s Digest articles like this one online learning about its many uses. Thanks for the education; someone else mentioned it, but after two times I came to attention and started learning more.

  24. Lydia says

    Hi Margaret,
    Here’s my anti-slug formula. I mix up a spray bottle with 1/3 ammonia to 2/3 water. I just spray the slugs and that’s it (they melt). I got this recipe from a shade nursery here in coastal Maine and it works really well. Thanks for your wonderful website.
    Lydia

    • says

      Welcome, Lydia. Thanks for the hand-me-down recipe, all the way from Maine. Happy to have you with us, and just to be here in general; nice of you to offer encouragement. See you soon.

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