An easy way to kill a slug is by sprinkling salt on it. I don’t exactly understand how it works but the slug sort of just melts and squishes itself up and dies. A couple of days after killing it the slug is completely dried out. You might not want to be so cruel so here are some ways other to prevent and eliminate slugs and snails.
We will start off with containers. This can also be done to your porch or any place where the slugs might venture up on. A thick layer of petroleum jelly around the area that the slugs are crawling on will prevent them from climbing up. Slugs and snails can easily climb up onto a container and eat on your plants. Petroleum jelly is too slippery and they will fall right off .
If you do notice a large amount of slugs and snails you should probably remove them. Snails can be relocated easy enough. My advice on the slugs is to just kill them. I really hate slugs though. During the day you can see them, but at night you will need a flashlight to see their shiny trails. Slugs and snails can easily be drowned in a bucket of soapy water.
You can purchase diatomaceous earth and spread it over your garden where the slugs and snails are inhabiting. Diatomaceous earth is tiny, sharp granules and will cut the bodies of the slugs and snails as they crawl over it. Diatomaceous earth has to be reapplied after every rainfall.
Take shallow disposable pie pans and fill with beer. Snails and slugs do not like yeast. The snails and slugs will fall in and they will drown. Check every day and remove the dead ones. Refill as needed.
If you do not want to waste money on beer than you can mix up your own mixture. Add 1/2 teaspoon yeast and 1 Tbsp. sugar to a gallon of water. Fill your pie pans with this mixture for the same result as store-bought beer.
Do not let trash, woodscraps and such pile up around your property. This will harbor snails and slugs because they like moist, dark and cool spots.
Snails and slugs can do a lot of damage to many types of plants so it is best to destroy them as soon as you notice a problem.