A mulch of autumn leaves breeds an army of slugs

IThe Oregonian
was out checking the dregs of the vegetable
garden when Doug the Wonder Guy approached me looking stricken. "I did it," he said. "I'm the guilty party."

I wondered what on earth he was talking about. Had he pruned my chocolate mimosa again? Had he eaten the last piece of pie sitting on the kitchen counter? Had he let Ernie the dog escape from the yard?

"I'm responsible for the slugs this year," he confessed. Since he looked so bereft and contrite, I resisted the urge to whap him on the side of the head with a cabbage and, instead, listened to his story.

It seems DTWG had a bright idea last fall, which I have to admit sounded reasonable. Instead of putting all of the fallen leaves into the compost pile, why not rake a bunch over our flower beds to act as winter protection? That part of the plan worked. Even a newly planted crape myrtle survived last winter.

But the carpet of leaves also did something else. It provided a perfect habitat for slugs to crawl under and deposit their eggs. Leaves are airier and lighter than most mulch but still retain moisture and some measure of warmth.

Hence, by spring, I had half the world's slug population bounding out from underneath their leafy nursery and heading straight for the shoots of my newly emerging plants. Over the summer, as I've whined about slugs ad nauseam, kindly readers have sent me slug remedies that will not harm my pets.

Reader Linda Taylor swears by the herb borage, which she says slugs loathe. She places a borage plant at each corner of her vegetable garden and among her tomatoes. Roger Ferguson asked if I was aware of the corn gluten-based slug remover, and no I wasn't. He says it is quite effective in getting the "little dears" to go away permanently and is still kind to the environment.

Darlene Sanman passed along advice that slugs prefer the thin-leaved hostas. I have noticed that they don't touch some very thick-leaved greens, such as Podophyllum, that enjoy the same conditions as hostas -- shady and moist. Truly, it helps to have a thick skin.

Carole Trenko wonders if I've tried late-winter slug control with ammonia. She credits this advice to the late Elsie Skinner, longtime president of the Northwest Hosta and Shade Gardening Society. In late February before shoots emerge, she advises sprinkling about half to one cup of a mixture of one part non-sudsy ammonia and four parts water onto the crown of hostas and other susceptible perennials. This does in the slug eggs.

There seem to be dozens of environmentally friendly ways to control slugs. All work to a degree. They probably can do in a zillion slugs, but my problem is that I have about a centillion. I think, given DTWG's epiphany, that the most viable solution is to smash or spray the ammonia mixture on the eggs during winter. They are, I'm told, underneath anything dark and moist, such as boards, pots and, alas, masses of leaves. They look like milky-white caviar (sorry if I've put you off that delicacy now).

Otherwise, if they hatch, my slugs will mount armies and march forward with impunity in spring. No matter that they lose companions to boiling water, diatomaceous earth, salt, copper barriers, beer, oat bran, ducks and chickens, salt and various spray mixtures. There are still enough survivors to munch everything in their slimy path.

And, of course, I will try readers' suggestions. This is war, after all, and I am glad to have allies. And I'm really glad that baby slugs are not cute.