I used to be squeamish about slugs. To separate them from the tender seedlings they were eating through, I’d use garden scissors as tweezers, or the point of a knife (both of which could subsequently be used to terminate the offender). Initially, I used dishes of beer to trap them. This was very effective, if you measured effectiveness by the number of slugs and snails trapped, but if your metric was the survival rate of your seedlings – not so much. Slughelp.com, written and run by I’m guessing an Extinction Rebellion activist from Germany, says slugs love beer so much that I was actually drawing them in from the entire neighborhood. I started visiting my garden in the dark to catch them eating cucumber bait under pieces of wood or munching on my stalks of onion. Slughelp recommended I drive the arrestees a mile to release them in the wild, but this is tall order even for a fellow Extinction Rebel. His stated rationale was not so much humaneness as a claim that slugs are cannibals that are attracted by the smell of dead slugs. This is too macabre to be credible even for a slug.
But something inside me broke when I found them climbing over each other to get to the peanut butter bait in mouse traps set up to catch voles.
I lost my squeamishness. I thought nothing of picking up the slimy mollusks between my thumb and forefinger and drowning them in a tub of soap water. I could do this all day and night. And I would have to unless I took other measures. I put copper rings and plastic collars with downturned rims around the seedlings. Apparently, copper gives them an electrical shock and slugs have trouble climbing around the rims. These are expensive and laborious solutions that work, but not 100% of the time. Rainy days activate the slug army. Where do they hide on other days? Speculating on this requires some background.
Permaculture is a form of agriculture that recognizes, respects, and benefits from interactions among the various natural and man-made entities present on a farm, be they ponds, plants, prey, predators, prevailing wind, walls, rocks, mulch. Mulch is any material – straw, woodchips, compost – used to cover bare soil. Mulch occupies a nearly talismanic position in the world of permaculture. It keeps the soil moist, thwarts weeds, shelters friendly creatures like earthworms and spiders. And even unfriendly creatures like slugs, the minority English were saying on permaculture forums. Permaculture was formalized in the dry climate of Australia, these residents of a famously moist island were pointing out. Do not fetishize mulch, they were pleading.
So far, I had loved mulch. I rarely needed to water my garden last year. The straw slows evaporation from soil on hot days and holds on to extra moisture on rainy days. When I sowed cloves of garlic last fall, I covered the bed with dry maple leaves (another form of mulch). The garlic came up through the mulch in early spring; the soil stays forever moist under the dry leaves. I never water that bed. But the slugs broke me.
I took the mulch off all the beds but garlic. We had a string of warm, dry days. I put the mulch back on the tomato beds, which slugs don’t seem to frequent. We had a rainy day. Some slugs came back. I killed those I found. Then again warm and dry. Slugs retreated. They returned with the next rain, but in diminished numbers. As we enter hotter months, the mulch will go back. It will come off for the fall when – per slughelp.com – the eggs of next spring’s destruction are laid under mulch. This might also discourage the Devil’s Coach Horse beetle, a slug predator, but ah well, in the ying and yang of the elements that you tweak and tilt to yield human sustenance, you make choices and take chances.