Bleeding hearts do fine in zone 3. I'm sure they'd do fine in zone 2. They're one of those plants that would survive a nuclear war.

Bleeding heart is a very hardy perennial. It does great in my zone. Are you referring to the US zone numbers? I am in zone 1b on the Canadian zonal map which is equivalent to US 2 or 3, I think.

US Zone 1, we get lows of -70 F at least once a winter. I think that is about -56 C. Any specific recommendations? Muchas Gracias!

My thermometer only goes down to -45C, which is also -45F at that point. When it actually gets that cold, it's my idea of hell. I don't want to experience anything colder!
Where are you? What grows in other gardens there?

Fairbanks, which is interior Alaska. we get the temperature extremes: 80 degrees in summer, and 70 below in winter (F). (These are extremes--I was born here and I would pack up and ship out if we go 2 months of -70!!!)In terms of perennials, we can grow them: irises do really well, rugosa roses are the plant version of cockroaches:), siberian peas, hardy lilacs, spruce. We can (sort of, with protection) overwinter garlic and asparagus. Plant out date is June 20th, 1st frost around end of August, but most of us use cold-frames, greenhouses, cloches, raised beds, clear plastic, etc to get a jump start adn extend teh season. We work pretty hard to provide a microclimate in our yards. But Nome has it worse, at teh top of AK, they don;t really get temperatures above 60, adn spend a month longer in winter.