I have had to go out at night latly and catch those buggers, never seen them on zinnias,impatians,balloon plant,I have seen lots on rudbeckias, marigolds, primroses their favorite. Good luck

They also love Nicotiana.

Malope in my garden.
Marica

Malope too? So disappointing... I do the hunt and squish method, and I tried nematodes (available here in the UK), but still the plague goes on. They ate my marigolds, ate the coleus. Ate my gentian buds. The balloon flowers were okay for quite a while until one day recently I went out and found nothing but slime-covered stems left. I think I'm going to have to try the iron phosphate, but I worry that it might get very expensive... do I really put it around EVERY plant that slugs like? And reaply after rain? It's the UK and we get LOTS of rain... and I have a lot of plants... I don't know.

I'm also in the UK (London). Now the drought has ended (very little rain for a year and a half here in the South East!) the slugs and snails are making themselves very visible again. I use the iron phosphate pellets, and they do work. As with all slug pellets, you apply them very sparingly rather than in big clumps. I have a big garden (175 feet long), and a container of pellets still seems to last a long time. You can get rain-proof pellets, but you'd probably need to reapply them if there's non-stop rain for weeks on end (although I think you're only supposed to apply them a maximum of 4 times in the growing season, or something like that). Do give them a try (they were quite cheap in B&Q last time I looked, or was it Homebase? About £3.50 a tub).

Sweet peas, too. Protect your sweet peas from slugs and snails early. Nothing worse than going out and seeing your little darlings mowed down overnight!