I had read somewhere to crush up eggshells and scatter them around your precious hostas & iris's so the dreaded SLUGS or SNAILS (UG!) would not munch on your tender emerging shoots.
I had been saving up eggshells - we hubby & self been eating an egg a day, so finally I had a icecream bucket (4 litres) full of rinsed out eggshells. I then put them in the Cusinart and whizzed them around till I had broken up the eggshells, not too fine, glass shard like.
Went out 2 days ago and spread them around my hosta and iris bed. Today went to look and what did I see but a smear of what looked like spit. But I know better, it was a slug or snail who had gone over my eggshells. Zapped him good!!
I am still saving up eggshells, even if I don't need them for the hosta & iris bed then will add them to the compost heap.