Throwing out garden pests instead of killing them

My mother grows organic vegetables so she doesn't spray pesticides. I warned her that killing snails would add to her karma of taking life; she said, "If I don't kill them, what will I eat?" So she no longer smashes the snails on the ground to kill them — she puts the snails into a plastic bag and throws them in the trash. Is that the right way to handle it? What other alternatives are there?