I know things like egg shell and coffee grinds are meant to be good for keeping slugs and snails off because they don't like the feel of it. But, alas, I don't drink coffee much and I don't eat eggs.
Someone told me that course sandpaper also detered them, just staple it to the sides of the raised beds and they won't climb up anymore. Not heard of this one before but it seems to make sense. Anyone else tried it and can report on the results? I'm thinking wet'n'dry rather than sand paper as it ought to last longer and being black it should bring more warmth to the bed.
You need to be careful as they may learn to abseil in over your obstacles!
I would have thought that the wet and dry stuff may not be coarse enough! Also isn't it made using something like fish glue on the scratchy side. It may even encourage them - I honestly don't know though as I haven't tried it!
Old Bird
;D
Sandpaper is no good because when it rains all the roughness is washed off.
Your raised beds are probably made of timber i presume. You could get a cheap jar of vaseline at a drug store, smear it on and sprinkle with a tiny pinch of salt. Or if you're so inclined, protect the plants they love with rings cut from pop bottles, smeared with vaseline. Or if you can find any these days, the copper scourers, unravel one of those and loosely attach to the sides of the bed. I say loosely, as it makes gliding over rather dodgey. I must admit i don't have ground coffee, but the egg shell theory never worked for me. and besides which i have more important uses for egg shells.
I eat lots of pistachios, I smash the shells up in a blender then sprinkle them round my plants, they are razor sharp, far sharper than egg shells.