Snails may have arrived by hitch hiking on nursery pots or in the soil of new plants. They multiply in wet weather and damp places. They can be controlled with garden clean up and by using a slug bait like WorryFree, or Escargo. You can also go out after a rain storm and stomp, pinch and pick them from the plants. There are also native snails in Western Washington that thrive in shaded ravines and cool green woods and get quite large compared to the small garden snail that eats young and tender plants. Keep growing, Marianne Binetti .