(…and one tantalizing future possibility)
Q. I am writing to you from The United Arab Emirates, where the weather is often lovely, the sun is always warm and the flowers grow beautifully but my garden is a disaster area. It has been invaded by hundreds of tiny little snails. They attack the plants at night and hide during the day. They are everywhere.
I tried spraying with Malathion but they still chewed to death everything--geraniums, impatiens, periwinkle... What can I do??? PLEASE help. Thank you!
--Wadad Cook; School of Business, American University of Sharjah, U.A.E
A. Thank you Wadad! Your asking this question will help reassure our poor mollusk-munched American listeners that snails-and slugs, which are simply snails without the half shell-are a universal problem. Here are 17 methods anyone can use to try and stop either creature from devouring precious plants:
1) Buy 'em a Beer. But not stale beer! Research has shown that slugs like stale beer about as much as I do. It must be fresh-so wait until dusk to fill your slug traps; otherwise the beer will go stale during the heat of the day and repel the slugs (and me). A number of commercial beer traps are available; and if you decide to go the old margarine tub route, be sure to leave an inch or two of the container above the soil line. (We'll tell you why in #2). In the morning, your containers will be filled with dead drunken slugs. Use the cheapest-but freshest-beer you can find, preferably one with a real yeasty smell. Ask your beer distributor if you can capture the excess when they drain return edkegs; they generally pour a lot down the drain when those 'three day weekend' kegs come back.
2) Be kind to Rove beetles. Those big black beetles you often see in the garden don't bother plants, but do eat LOTS of slugs and their eggs. Always leave an inch of your beer traps above the soil line so none of these very beneficial insects accidentally fall in.
3) Let Lightning bugs shine. The larval form of these great entertainers looks nothing like the adult; "glowworms" (their actual common name) are segmented, wingless, and look like sow bugs or pill bugs, but already have that distinctive built-in flashing light-and these hungry babies eat lots of slugs and their eggs. To encourage the adults to breed near your garden, don't use lawn chemicals, turn off outdoor lights at night, and allow a small area of your garden to stay moist and a little weedy.
4) Toads, too! Avoid ALL pesticides, provide water low to the ground and a damp shady spot for them to hide during the heat of the day, and these wonderful nocturnal predators will eat lots of slugs for you.
5) And Ducks! These feathered friends are perhaps the best slug-eaters of all! And, all together now: "We can always use the eggs". Thank you.
6) Protect your crops with Copper. Slugs get an electric shock when they touch the shiny metal. You can buy ready-made copper plant guards or just adorn your raised bed frames with copper flashing and hot-glue rings of pennies around the tops of containers. Drop captured slugs into a jar of pennies and watch 'em spark!
7) Dust 'em with Diatomaceous earth. Available at garden centers, 'DE' is the mined fossilized remains of dinosaur-era, sea-going creatures called diatoms. Looks like flour to us, but is incredibly sharp on a microscopic level, and dehydrates slugs on contact. (But it doesn't work when wet.)
8) Irk them with Iron phosphate. Old chemical-based slug poisons like the malathion Wadad mentions are nasty, nasty toxic and cause a lot of collateral damage to birds, toads, pets and people. But this new generation 'molluskicide' uses regular old iron as its active ingredient. The iron is combined with a slug-attracting bait to make products with brand names like "Sluggo" and "Escar-Go!". Safe for wildlife; death to slugs. And the little bit of left over iron is actually good for your garden!
9) Betray them with Boards. Lay some old planks between your garden beds. The vampiric slugs will crawl underneath them to hide from the sun. Come morning, lift the boards and scrape the slugs into a bucket with a flat piece of metal. Then do what you will. Got any pennies?
10) Catch them with Citrus. Leave a bunch of lemon, orange and grape fruit rinds out overnight near slug prone plants and then collect them-covered with slugs-first thing in the morning. How's them pennies holding up?
11) Harass them with Human hair. Stop in at the barbershop or beauty parlor, ask for that day's clippings, then surround your plants with a protective barrier of thin layers of hair. The slugs will get all tangled up in the hair and slowly strangle. (Hey it was them or the hostas!) And the hair adds plant-feeding nitrogen to the soil as it slowly decomposes.
12) Spear Some. Get a flashlight and a long Shish-ka-bob poker and go to town one nice evening-you deserve a little nighttime fun with a sharp stick. Leave impaled slugs behind as a warning to survivors.
13) Salt your slugs. No, it's not good to use too often, but it's OK to get a little bit of salt in the garden every once in a while--and very emotionally satisfying. You don't need to cover the poor things; find a container that releases just a crystal or two at a time. You only need to sprinkle one little grain on each slug and its orange goo by morning, baby!
14) Or season them with Vinegar. A spray bottle filled with plain white vinegar is a great cure for slugs that aren't on plants. An extremely effective mollusk dissolver, vinegar is also an herbicide-so don't spritz the salvia.
15) Or Garlic. New research has shown that garlic kills slugs. A British garden supply company sells garlic granules for this purpose, but I'd simply soak the garden down after dark with one of those new garlic sprays sold for mosquito control, like Victor's" Mosquito Barrier". It should kill lots of slugs, and keep skeeters away for a good two weeks. It might even repel larger pests, like rabbits and deer!
16) Make them a cuppa Coffee. Even newer research found a coffee-based caffeine spray to be very effective at dispatching slugs. If I've got my percentages correct, you'd simply need to brew up a strong batch of Joe, let it cool, and then spray it, undiluted, on the garden at nighttime.
17) Practice your Long Toss. Put on a pitcher's cap, go out to the garden and hurl the nasty slime balls into the road while you listen to your favorite Major League team blow a lead. Clean up with Brillo.
And, coming soon (we hope!):
- Douglas in Lawrenceville, NJ and Marc from Milwaukee both emailed me recently about "Nemaslug", a British company's brand-name for a species of beneficial nematode that attacks slugs. I checked it out and its true. This very special beneficial creature is, like all nematodes,so microscopic that their kitchen-sponge sized container holds millions of them. But Unlike other nematodes, they survive above ground as well as below, and prey on slugs and their eggs!
- And it might be easier to find one than you think. It turns out that slugs who have been attacked by this nematode develop a kind of saddle-like structure on their backs. Find a slug with that distinctive physical marker, and you'll likely have found the nematode as well. We'll post a link to a photo of a slug with a nematode-induced saddle so you know just what to look for.
You Bet Your Garden ©2004 Mike McGrath