I'm actually interested in a fruiting quince, not flowering quince. (Though I just googled images and they are lovely.)

Every spring it had beautiful white sweet smelling flowers. I was looking forward to finally getting fruit this year, but our hard winter froze the quince 3 feet down the trunk. It has set out shoots now, but I don't know how well it will do.
I also had a cherry freeze back to just the trunk and a few short branches.

The flowering quince is Chaenomeles speciosa or C. japonica and hybrids, etc. With a good microclimate and mild winter, I could see it being somewhat (but not reliably) hardy across most of Minnesota. As one mentioned, easily with severe dieback if not fully protected under snow in Jan and February. The small fruits of flowering quince are edible, but they are tremendously bitter.

Thanks to the highly misleading modified USDA zone hardiness maps sent out by the Arbor Day Foundation, nurseries are feeling empowered to bring in marginally or fully unhardy plants into new regions, mainly for $$$ (market share). :(

I was just out there this week, and both of them are still alive! They suffered some dieback, but that was to be expected. The location was a somewhat sheltered region (eastern side of our windbreak, backed up by 3 rows of spruce and red pine to the west). I didn't get the bales of straw around them for insulation like I had planned on, and we didn't have another mild winter like so many previous years. They are back to their original 1 ft height, but the regrowth is looking very vigorous. I'm hopeful that if I baby them the first few years with straw bales and piled snow for added insulation they'll make it on their own later on.

It remains unethical, however, for nurserymen to blanketly say "it'll grow here", in particular to the general public who will drop cash on plants and have no clue of difference in light exposure, know what deciduous, or tropical bulb means in the greater scheme...

So, you're tell me that everyone of you would bet your life on the FULL HARDINESS of plants in microclimates in the Twin Cities would just as reliably survive the same zone 4a and 4b winters say in St Cloud, Mankato or Windom?

A plant that "survives" a winter and has to rejuvenate annually or putters along may be "hardy", but saying such a zone 5 or 6 plant is fully hardy in zone 4 or 3 Minnesota without clarification or explanation is BOGUS.

It's like the man in Iowa who grows Washingtonia palms with consideraable babying and wrapping/heating in winter telling people that these palms "are hardy" in zone 5...there is a difference to man-made manipulation and cultivation than natural factors.

Catalinagray mentioned having a Cydonia quince, but lo and behold a Minnesota winter knocks it back to 3'--so are you going to say this tree is hardy? Will it set fruit? Why don't you go to the local nurseries, including Bachman's or Linder's and boldly tell their nursery manager to start a new promotion and stock up on half-hardy, "iffy" plants to sucker the average consumer?