I buy according to the temps I know we have had and it is capable of here. That is negative 10. technically the zone I am in is not that low, but I don't trust my money on it. Map says zone 6, but the weather here is actually zone 5. So when buying plants I look for hardiness down to zone 5. Otherwise you will end up replacing it sooner or later. I do plant semi tender bulbs sometimes, just plant deeper than it recommends and they usually come back, although not as gloriously as in warmer zones. But then again that odd year will strike and they will die. So I plan them to last 2 or 3 years or whatever.
