Tuesday, April 6, 2010

Slugs - Big, Bad and Slimy!

You know they’re out there. Perhaps they’re hiding under the wide, sheltering leaves of your hosta, or perhaps beneath that damp pile of leaves placed casually to the side of your garden. They may even be biding their time under a stray piece of wood until night falls and they slither out of their hiding places to start dining on your garden!

Over the years, I’ve heard hundreds of slug-based horror stories where entire gardens were completely defoliated in one night by hordes of slimy slugs. Although these stories may be slightly exaggerated, it is true that slugs do prefer to feed at night and they are at their peak in damp, cool weather – gee, have I just described a Maritime summer?

It may still be early spring, but the slugs are out! After our Easter Egg Hunt in the backyard this past weekend, we found about a dozen baby slugs that had crawled inside the holes in the plastic eggs looking for a chocolate treat! Yuck! (And for the record, the plastic eggs had only been outside for about a 1/2 hour, so those tiny slugs moved pretty quickly!)

Slug eggs are laid in masses and are deposited under leaves, garden debris or in the soil. In about a month, the eggs hatch and the young slugs, resembling the adults in all ways except for size, begin feeding.

Slugs will feed during the day, but only in damp, shady locations, as their trek through your garden is dependent on moisture availability. They move by gliding on a trail of secreted slime, and it is this silvery slime that is often one of the first clues in identifying a slug infestation.

Over the years, I have spent countless summer evenings sinking beer filled containers into the soft soil between the tomatoes. Of course, soon after the traps were placed, it would invariably rain. The beer would be quickly diluted by the water and run over the sides of the containers, rendering the traps useless.

Why are slugs attracted to beer? It is actually the fermenting yeast in exposed beer that tempts them, so for best results, open the beer several days prior to baiting the traps to allow it to ferment. To save some money (and the beer for yourself!), you can also use a spoonful of yeast in a container of water to lure slugs to their untimely demise!

One way to prevent rainwater dilution is to use an empty plastic 2-liter pop bottle. Fill it with enough beer or yeast water so that there will be at least an inch of liquid when it is placed on its side in the garden. Put the trap in a shady, damp location or nestle it near your besieged hostas. The little suckers should be attracted to the fermented yeast, slither in and drown.

Besides plying slugs with alcohol, there are several other natural solutions that seem to harbour some effectiveness. Copper wire is said to give slugs an electrical shock when they come in contact with it. For best results, place one-inch wide bands of copper wire around your hostas, vegetables or even individual garden beds.

Other homemade traps include a moistened folded newspaper, wide boards and flat rocks that may be placed in the vegetable garden, near perennials or even beside your compost pile. Check each morning and discard any discovered slugs.

Gritty materials such as diatomaceous earth, sharp sand and crushed eggshells may also be sprinkled around plants to deter slugs. Regular tilling in the vegetable garden will destroy slug eggs, which are often deposited beneath the soil surface. They look like tiny crystal balls and can easily be crushed with a gloved hand.

The best defense is a combination of the natural controls mentioned above and practicing good garden sanitation. By removing piles of leaves and other garden debris you will be eliminating many hiding places and breeding sites. Perhaps the slugs will get so fed up, they’ll pack their bags and slither on over to your neighbours garden and her prizewinning peppers!


  1. I went to the local scrap yard and got some sheets of copper that are used in the manufacturing of large electrical transformers.Sold by the pound,it wasn't too expensive but worked 100 percent and is reusable each year. I had to cut it in smaller strips but got close to a dozen for less than 5 bucks.Good for cabbage where slugs like to burrow inside... pete

  2. Also should add that slugs get a jolt out of zinc as well.It is easier to find as it is used to keep moss off a roof and sold in a strip. You need 2 inches I think to be effective but not positive...maybe less.

  3. Good ideas Pete! I love your copper idea.. Not only does it sound economical, but you're recycling!

    A friend read the post and said that they feel sorry for the slugs - obviously not a gardener! :)

  4. ok,one more thing.We have wild ducks and lots of crows around.I know the crows eat slugs, and I kinda think the ducks do too.Very helpful! pete

  5. Yes, ducks eat slugs, so do geese. Hens will eat one if they are competing against other hens for what you bring them, and then decide they don't like them. I think metal needs to be wide enough so whole of slug is on it at once, but perhaps not, since that copper wire worked.

    I have built electric fences around boxed beds: 1 1/2 - 2" finish nails for fence posts, spaced in pairs about 1/2 to 3/4 inch apart and at 12" or wider intervals around the box top. Drinking straws cut in about 1" pieces for insulators around each nail. String thin copper wire from fencepost to fencepost, taking a turn around each insulator (straw) until you get to the other end. Attach the wires to a 12 volt doorbell transformer (I assume they still exist) according to its instructions, plug into house current (110 volt and too much to be safe for people & pets) and let it electrocute - or simply deter - slugs from crossing. They have to be on both wires at once to be electrocuted. If you feel sorry for the slugs, I suggest putting them to good use as a source of protein. Deep frying in batter might be palatable. Or build a slug haven under your kitchen sink.


Please feel free to leave comments. I welcome your tips, questions, thoughts and ideas (and suggestions for new veggies to grow!)