Hardiness questions

[S.& R. Illingworth]

Our optimism about some of our arisaemas may be misplaced.  Amurense came
up, good and early as usual.  A. sikokianum is there, as is flavum.
However, no sign of A. ciliatum or ringens.  I dug down in two locations and
found rotten tubers. Is it too soon for me to give up on A. consanguineum?

Last winter was an easy one on people, but harder on plants than the
previous winter's prolonged severe cold.  I chalk it up to a very wet fall,
then a sudden plunge into the deep freeze with temperatures to -18C for 3
weeks before the snow came (the coldest temp. with snow was -38C).  We also
had a prolonged slow thaw this spring.  Maybe it was just an exceptionally
bad winter.  Other supposedly very hardy things suffered as well. Roscoea is
up and looking great. We'll try again.

Our ACE plants are still in pots; we intend to overwinter them in the root
cellar, and then put them in the garden next spring, to be dug up in the fall.

Sharon
near Thunder Bay, Ontario
USDA 4,
Min -40C/-40F with snow
Min without snow -20C/-4F
Max 30C/86F, rarely higher
Frost free days 110 on average