Garden Pests and Diseases: Snail damage?, 1 by livingparadox

livingparadox wrote:
Hi there,
I'm assuming this is snail damage, but im not entirely sure because i couldn't find any silvery trails (it has been raining alot lately so they have probably washed away). I know the reddening is from the recent cold weather, I actually think it looks quite pretty. But im just looking to confirm the snail theory, could there possibly be more than one pest causing this damage?
How would I treat this problem and how long will it take for my poor sedum to recover?

Thanks :D