Just chimeing in here.I plan to offer this as a Tip of the Day as soon as Hostas peek out of the ground here.Probably late April.
I have cut down on the slug population here by drenching the ground around the emerging plants.
As soon as I see the hosta eyes I treat with Amonia diluted 1 cup amonia to 8 cups of water. The sluggs are not in the armys they use to be here. Snails are another matter.
I also treat Ligularias as they emerge. Slugs on those leaves are really damaging.