Slug Necklace

It is said that slugs dislike crawling over copper, and cardboard is a good weed barrier. I have been battling the slugs turning my ligularia into swiss cheese (not a good look when my main draw to this plant is the gorgeous foliage), so I am trying a new tactic this year. I found an appropriate-sized bowl that fit nicely over my plant, and used that as the inside diameter on a piece of cardboard. I then simply measured out about 5" and drew another line. Cutting would be easier with an exacto knife, but I just used kitchen shears. I then glued pennies all around the collar, beginning at the inside and working my way around. Again, I used what was on hand (Elmer's), and I'm not really sure how that will hold up outside. I let it all sit overnight and then placed it around Ligularia 'The Rocket' and Bigleaf Ligularia (Ligularia dentata 'Othello') (even harder hit by slugs; not sure why), tucking it down into the dirt so there is not a slug pathway under the cardboard. I plan to also spray inside the cardboard and around the emerging plants with a weak ammonia mix, as recommended by others as a slug deterrent. I'm hoping this will do the trick. Meanwhile, I kind of like the look: rather like the plant is wearing a crown or necklace. Most of it will be hidden as the plant gets taller.