I just love Hostas, I have about 50 different ones, most of my dwarf hostas i keep in the green house in similar settings to a alpine house, the larger ones in the garden, i find the only way to keep slugs and snails at bay is to check them every couple of days in the early evening or after it has rained, collect all the snails and slugs up in a plastic contains and on the way to work which is along country lanes i let them go theres no houses about so they will not trouble anybody else they have to live too, but not in my garden you will soon cut their numbers down in your garden.