Wouldn't worry too much about them, mine have been up, in full foliage, since late January and have survived temps as low as 18°F. They didn't bloom this year, but that's not unusual either, as they seldom do. Also, had two species of Arisaema (ringens & undulatifolium) emerge at about the same time. They both bloomed, but were somewhat affected by the sub-freezing temps.
We were there last week for The Flower Show and it was cold all week. Started to warm up on the weekend, as we were leaving! Talked to friends there this evening and they said snow was predicted again tonight. We are expecting freezing temps this weekend and we are 700 miles southwest of Phila.
That darn groundhog lied again!
Rb

Hi George,
Mine usually break ground in late Feb, to early March. They are about 6" high now. Sometimes the frost may kill a few leaves but it does not seem to hurt them.
I just noticed some of Jack in the Pulpit I received from you in a trade last year are popping up. I'm looking forward to seeing them grow.
Jim