I would never put down slug pellets again.They kill the hedgehogs and the birds, that eat the slugs and snails.
Too bad if they eat the plants, just try different plants that they don't like.
Gardeners World tip for pot plants.
Put the pots on one of the dish/bases you can get to stand them on, and fill it with water. Plants will only take up as much water as they need, and slugs and snails won't cross the water.
Seems good to me.