At one time, I had a garden on both sides of some tall bushes. Ground beneath littered with leaves, it was happy slug country.
I had a "shade garden" elsewhere but thought that I could grow a little lettuce 4 feet and a little beyond those bushes. The slugs tried to invade!
Out with some organic spray of one kind or another, probably Bt, I thought to spray the 4' ground. After running the sprinklers a few days later, I was out again with a different spray. I remember that it was different - let's say that it was insecticidal soap. I sprayed the ground again.
What I learned was that slugs don't like to slime their way across some things.
I once made the mistake of planting a few tomatoes where they ended up sprawling across some lawn grass. Beyond was a garage and a well-shaded area of lawn. I could NOT keep the slugs out of those tomatoes. They took the whole crop!
Will a band of crushed eggshells stop slugs and snails? We test to find out what REALLY works. The results surprised even us. Read on to find out.
I have used buried beer cans in the past successfully. You buy the Cheapest beer out there and sacrifice a 6 pack. I HAVE used it and it DOES work. Just poured out a super bitter ale that somebody brought to my house to share and NOBODY could drink it. UNfortunately, it was in bottles, so I poured the beer out to feed some of my tomato plants. You can do the same with spoiled milk, instead of sending it down into the water treatment plant.
Another help is to WEED around your plants and put down mulch, which can be grass clippings if you have nothing else.
Also, if you are a coffee drinker, I recommend using the grounds to repel slugs.