Slug Prevention: This Year’s Method


Copper tape applied around the perimeter of our raised garden beds

Being in a bit of a hollow, most of the time our little acreage stays pretty damp and cool.  Where the garden is concerned, that climate is a mixed blessing.  While we rarely have to irrigate, crops like tomatoes and peppers could do with a bit more warmth, and oh my, the slugs.  They seem to thrive here, and we’ve learned the hard way that their constant chomping can be a real problem in the vegetable garden.

In the past, we’ve tried a number of approaches to keep them in check: manually picking them off of plants and beds, luring them to their drowning doom with shallow dishes of beer tucked here and there throughout the beds, and sprinkling plants and beds with diatomaceous earth (a powder composed of the fossilized remains of a type of algae, it lacerates and thereby dehydrates whatever crawls over it).  All of these methods have worked to some degree, but they’ve all had their drawbacks, mostly related to user error/inconsistency.

Manually picking slugs, aside from being kind of gross, is time consuming and must be kept up very regularly to make much difference.  The beer works pretty well, as long as one remembers to empty and refill the dishes every day or so.  If not, the result is a vile, reeking, sun-stewed cup of skunky beer and rotting snail corpses that invariably ends up on your hands in the process of emptying.  The diatomaceous earth has been my favorite method so far in that it’s much more hands-off, but it needs to be consistently reapplied after every rain, which can become difficult (for us) to stay on top of.

The long and short of it is that we’re not great at consistency, especially on a daily scale, and while our half-assed use of all of these methods has amounted to less slug damage, I’ve been trolling for a more long-term, inconsistency-proof solution.

Applying copper tape around the top of garden bed

Applying copper tape around the top of garden bed

I’d read a few places that copper was a good slug deterrent in that it gives them a mild electrical shock when they come in contact with it.  I filed the idea away for a while as no easy, affordable ideas immediately came to mind for putting this wisdom to use.  Then one day I saw a post on a design blog wherein the author was copper tape – the sort used in finishing seams on stained glass – to embellish a picture frame or something.  Whereas I couldn’t figure a quick, easy solution for affixing copper wire tightly to the walls of our raised beds, this tape would be would lay flat against the cedar and even adhere on its own.

So I ordered a roll of half-inch wide tape from Amazon for less than twenty bucks. It was easy to apply and cut easily with dull scissors.

On the first bed I attached the tape to the horizontal surface around the top edge.  Then I realized that there were cracks between the stacked planks making up the walls of the beds and that a slug was probably more likely to enter the beds lower down.  So, for the remaining beds, I applied the tape to the vertical surface, just below the first chink.

I planted the garden around the first of May this year, and since then,  I’ve only spotted two slugs in the garden beds (perhaps by coincidence, they’ve been in the two beds where the tape was applied to the vertical surface, closer to the ground), which I’ve picked out by hand.  There has been some leaf eating here and there, but as I’m not seeing the slugs like I used to, I can only assume that it’s some other beastie at work, for which I’ve been applying diatomaceous earth every so often.

The only problem with the tape is that it has come unstuck in a few areas where I applied it to vertical surfaces, but I’ve just thumbtacked it back in place.

All things considered, the copper tape is shaping up to be the best line of defense against slugs yet.