Why is garden slug control so challenging?

Let's start with the obvious: Slugs are slimy and pretty darned disgusting. Most species are decomposers who feed on decaying plant and animal wastes. But, there are a handful of slug species that prefer to feed on living plant material, making them the bane of many gardeners. If you're reading this to figure out how to get rid of slugs in the garden, read on.

Note that not all species of slugs eat garden plants, but those that do can cause significant damage.

Unlike snails, slugs don't carry a shell on their backs. Instead, they have a small, saddle-like plate called a mantle. Because they lack the protection of a shell, slugs tend to feed primarily at night or on rainy days, when they're protected from the sun. During the day, they tend to hide under rocks or in other dark, moist locations.

Garden slug control can be difficult because many times the problem is misdiagnosed and the damage is blamed on another garden pest. Since slugs feed primarily at night, gardeners tend to notice the damaged plants, but they can't find the culprit when they search the garden during the day. So, the cause of the damage becomes a mystery and the gardener might choose to spray the plant with a general insecticide in an attempt to kill the bug, which is useless, of course, against a mollusk like a slug.

Slug damage is often blamed on other, more visible garden pests.

Aside from frequent misdiagnoses, getting rid of slugs in the garden can be problematic because good old hand-picking is both disgusting and super-challenging. Unless you're a night owl who loves roaming the garden with a flashlight and picking up slime-covered mollusks.

If you really want to know how to get rid of slugs in the garden, you first have to learn how to properly identify the damage they cause. Then, you have to understand how to target the slimy buggers effectively and efficiently based on how they feed as well as how they breed.

What does slug damage look like?

Slugs are notorious for decimating young seedlings and many different tender-leaved plants.

• If you come out to the garden in the morning and nothing remains of your seedlings but leaf mid-ribs and stumps, slugs are a likely culprit. Note too that:

• If there are perfect, round holes in tomatoes and other soft fruits.

• If there are ragged holes in leaf edges and centers.

• If there are lime trails on plants, walls, rocks, or mulch.

If there are chewed off seedlings with nothing but their mid-ribs remaining.

How do slugs feed and breed?

Slug mouths are lined with tiny, grater-like teeth that shred leaf tissue before digesting it. This type of feeding creates holes with jagged edges, rather than the smooth-edged holes often left behind by leaf-chewing beetles or caterpillars. Slugs move on an excreted mucus trail that serves to both protect their body from desiccation and message other slugs about their presence.

Most slug species are hermaphroditic, which means they have both male and female reproductive parts. Thankfully, slugs aren't capable of fertilizing themselves, so they have to find a partner to breed.

Each slug is capable of laying hundreds of eggs over the course of its lifetime, though the eggs are laid in clutches of about 30. The eggs are laid in moist soil, under mulch or rocks, or beneath leaf detritus. They'll sit dormant if the weather is too hot, too dry, or too cold, waiting for just the right moment to hatch.

(Adapted from "Savvy Gardening" by Jessica Walliser).