The Slugs and Snails only go after the young Coriander shoots, once the plants
are established I usually don't have any problems, but they like Beer even more than Coriander
so if you have a problem just lay down a couple of beer traps for them to swim in.
Other garden pests hate Coriander, I boil some Coriander up in tap water, let it cool, strain it,
fill the spray bottle. A natural remedy for aphids, red spider mite and the like.

cheers Chewy