I use those bottle-bottoms, 2-3" tall, for beer saucers to drown slugs.
I've been saving the tops to use as flimsy plastic "cloches" or hot caps to start seedlings a few weeks earlier - or rather, to nurse them through the weeks or months of hovering right around freezing that we usually have.
My hope is that such hot caps will also keep rain away from a tiny pinch of slug-bait, so the rain doesn't dissolve it in a day or two.
My experience with early seedlings and slugs, when slugs don't have much else to eat, is that either the slugs are VERY efficient at mowing seedlings off at ground level, or my neighbors pluck them with tweezers every single night.
I like the idea of using plastic bottles for cuttings!
Do you see the roots when they reach the edges?
