Tim,
the lowest we had was 11 F and an average of 26 F at night, mid 40's during the day. 3 days with a mix of snow & rain early april and 4 days of rain for the rest of the month. some of the hybrids started looking fine early April but looked pretty bad by the end of the month including the best looking filamentosa X rostrata(mailbox), I'm still clueless about what happened.....will post pics tomorrow