Getting Rid of Snails in the Garden?

How do you get rid of snails? I have been losing flowers for years. I planted smaller plants and they would eat the roots away so quickly. They can destroy up to 10 a night. I then planted over 80+ large plants going down the sides and across the front of my house. Still 5-6 plants at a time would be eaten over night, only a handful have survived. I don't really have a slug problem. I've used the snail and slug pellets, I've put moist things and pots down to gather them together and I've removed the snails early in the AM, but they are too many everywhere. The two pictures are after the snails have eaten the roots. Please help me :(