Slugs and snails are a huge problem in many gardens, especially those with tender-leafed plants that have lots of folds or large sheltering leaves low to the ground, such as lettuce, hostas and tender seedlings. Luckily, there are many ways to stop these critters.
1. Ammonia and water. Mix equal parts non-sudsing ammonia and water in a spray bottle. Visit the garden on a rainy morning or cool evening and spray the slugs as they feed. This technique is most effective on baby slugs, which thrive in the crowns of hostas and daylilies. As an added bonus, the ammonia converts to nitrogen and acts as a foliar food for the plants. (Note: Some ferns and seedlings may suffer leaf burn from this spray. Test on a single leaf first.)
2. Vinegar and water. Mix two parts vinegar and one part water in a spray bottle. Spray the mixture directly on slugs you see or as you find them under boards or in the crevices of rock gardens. Be careful not to let the spray come in contact with plant foliage.
3. Wood ashes. A ring of wood ashes from your fireplace will discourage slugs from climbing up the stems of plants. Sprinkle the ashes in a band a few inches wide, but don’t let them actually touch the stem of the plant. Caution: If your soil is alkaline, as it is in many parts of the West and Southwest, avoid putting ashes on your soil or in your compost heap. They can raise the pH even higher.
4. A window screen. Cut an old window screen into long strips at least 6 inches wide. Sink the strips 3 inches into the soil so that a fence surrounds your most vulnerable plants.
5. Clay pots. Lure slugs away from your plants to where you can find and destroy them. Set out small clay flowerpots turned upside down and propped up on one side with a flat rock. These traps are attractive enough to use in container plantings.
6. Damp cardboard, rolled-up newspaper, grapefruit rinds or damp burlap. Position these materials around your garden to collect slugs. Gather the items each morning and destroy the slugs. Or move the slugs, “hotels” and all, to your compost pile.
Adapted from Yankee Magazine's Panty Hose, Hot Peppers, Tea Bags, and more for the Garden: 1,001 Ingenious Ways to Use Common Household Items to Control Weeds, Beat Pests, Cook Compost, Solve Problems, Make Tricky Jobs Easy, and Save Time (Yankee Books, 2005).