Same thing happening here. I believe it is the lack of sunny days in June (only 5) and the over abundance of rain and cool temps. Some buds are opening but many just turned yellowish and dropped off. Also have some rust just to add insult to injury. Oh well, next year they will be pretty again I hope.

Same here. Turn yellow and drop off. Such a shame I have waited two years for them to even get to this point. Some people can grow them and they survive like weeds. Yes too much rain here too but my friend's hollyhocks haven't done this. Also have had rust on leaves but as suggested have been taking them off. I still have some flowers though? Weird.