Preventing slug and snail damage organically in your Midwestern garden can be achieved quite easily.
Slugs and snails live in the shadier venues of the yard, particularly in poorly drained areas, under thick foliage, and within groundcovers. They need this protection, as the sunlight will literally dry them up. This is also why the majority of their feeding occurs during the night.
Slug & snail damage resembles irregular shaped holes in leaves. Other signs are the slimy trails left on the leaves or nearby ground. Some of their favorite plants include; sweet peas, hostas, strawberries, lettuce, potatoes, lupines, and tulips. They tend to not like woodier stems, leathery or thicker leaves, prickly stems, or pubescent leaves, as they are either too difficult to climb or are too hard to eat.
Populations tend to fluctuate between slugs and snails as their life cycles are different. Slugs lay their eggs in the summer, which hatch in a few weeks, whereas snails lay their eggs in the fall and they do not hatch until the following spring. With this knowledge, you can expect there to be more problems with snails after a mild winter, as more eggs will survive. Wet springs favor the slug population.
Preventing damage should start from last year’s observations, if possible. Most likely, if you had them last year in your garden they will be back.
Clear leaf litter from around susceptible plants. Don’t give them a place to hide.
Make a barrier of eggshells, twigs, or ashes around the plants as they don’t like to crawl over rough or sharp material. Copper wire or pipe is also effective, relying on the premise that the copper delivers an electric shock to them.
Provide a halved orange upside down as bait at night, and remove the takers the next morning.
Use a shallow lid buried in the ground and fill with beer or lemonade. Slugs and snails cannot resist a free drink, and will come and drown in the pool.
For smaller plants, make a cloche by cutting the bottom off a plastic bottle, bury slightly, and remove the lid for ventilation.
Encourage frogs and birds to your garden as they can’t resist a meal of escargot!
If you’d like to know more: openlibrary.org has, “The Fieldbook of Illinois Land Snails”