Q.jack in the pulpit
I have six plants in pots that I brought to Salem, NY, Zone 4. I have been growing them in the ground in Brooklyn for over 20 years. 2 yesrs ago, I dug up the mother plant and divided them. I planted two bulbs [corms] in Salem which did not survive the winter. Since I am no longer in Brooklyn, what can I do to make sure I do not lose these plants over the winter?

my plants were planted in my woods and come up every year and have multiplied as you wrote yours did...before you moved them...I would put them in a shady area that is not disturbed and if put under trees will be naturally mulched by the fall leaves...I don't do anything to mine...I forgot them and remembered to look to see if they were alive and found at least 20 plants.....they produce an amazing seed stalk of red shiny seeds in a row at least 8 of them...try and harvest these and plant them to see if you can propagate them that way......b