Most are hardy to zone 4 or 3, so I'd say it isn't common for them. Did the crowns heave out of the soil badly?

Do you have root weevils there? They ate one of my Huecheras right off at the soil line. I didn't realize it until I touched it while weeding and the entire plant moved. I thought it just looked bad because of winter damage.

I don't know what root weevils are, and I don't know if I have them.

With the fair amount of mulch I put down, I couldn't tell that they had heaved at all.

Very disappointing, to say the least. Makes me a little cautious about getting any more. They're not exactly cheap plants, and I don't want to be losing them. It's surprising - they've always seemed like low-maintenance plants before now.

Deanna

Deanna, you could have lost them because it was too wet and they're roots rotted. Mulching them helps to stop the heaving, so that's good as long as you didn't cover the crowns, which you mentioned you didn't. I've had mine from 4 to 10 yrs and I haven't lost any. We had one winter where it went below 20 below. These past 2 winters we went down to 12 below. If you get more, or divide the ones you have, make sure the ground drains well. A lot of plants have problems when they sit in water during the winter.
Hope this helps and good luck! Heucheras are one of my favorite plants.

Kat

I lost a bunch of well established heuchera. That warm January and frigid March did them in and a lot of other things too.

I've lost heuchera before too. Too early for me to tell for sure on my ones planted last year. The plain old green leafed-pink flowered one seems to take anything Mother Nature can dish out. But some of the newer varieties seem to be chancy here in zone 4, no matter what the books say about hardiness. This past winter was brutal, and mulch doesn't seem to do the job that a good snow cover does.

Mine looked fine up until the late freeze we got in April. Is that what got yours Deanna or were they looking bad before that?
My Green Spice got through the freeze in the best shape. That would be a good one to try if you want to start over. Do you have that one yet? I'm curious which heucheras you lost and which ones you didn't. Do you know the names?

I'm still optimistic that mine will send up new leaves and I'm going to be sooo disappointed if they don't.

You might have better luck with one of the h. villosa cultivars ('caramel', 'frosted violet', 'bronze wave', etc.) Villosa is a really tough species. I'm 2 zones higher than you, so I can't vouch for its hardiness in sub-zero temps. But I can say that I have a h. villosa 'purpurea' that I've gotten away with neglecting by leaving it in a plastic pot with no protection over several winters. That means freeze and thaw over and over. It didn't mind in the least. It's supposed to be hardy to zone 4a.

I lost 2 Palace Purples and a Can Can. Can Can was my favorite!! I have 2 other Palace Purples that were growing just fine until the late freeze in April. It wasn't the late freeze in April that did in the 3, because all my other heuchera had come out of dormancy before that, and those 3 looked deader than doornails. They couldn't have rotted from too much moisture, because we don't get that much moisture around here in the summer or winter.

December was warmer than normal, then January and February were brutal. We had temps way lower than normal, and ice. Then suddenly, we had the 3rd warmest March in 200 years. Looney weather!

I had planned to get 5 more heuchera this spring, now I'm not too sure...

Deanna

Frosted Violet has made it through 3 winters, I'm hoping it'll show up again this year(still to early to tell here). I also put in Caramel last year and am anxiously waiting. We had two weeks of -20 degrees without snow cover this winter. I'm not as concerned about the temps in the teens in April because very few things had broken dormancy yet.

I agree villosa is the way to go for northern gardeners.
I have grown multiple heucheras from seed and hybrids and most of them are just not willing to put up with my garden for long. Palace purple has been long stand by and several of h. americana Dale strain. Love those purple varieties but they do not seems to be reliable for me.
I have been growing heuchera relative- tellima grandiflora green variety and now growing purple one from seed- I like them much better- they do not have as much heaving problem it seems.

It would be interesting to know what other people have lost. I lost 2 established Regina, a couple of 3 year old Palace Purple; plus some that were planted last May: a Snow angel, a Key Lime Pie and maybe another one or 2. All were well mulched, and this is a sheltered location too, compared to the rest of my garden.

Linnea - I don't know what I did right, but I didn't lose any of my heuchs. The only plants that croaked were Bergenia, which were in full bloom. My soil is very well drained and I mulched most of my heuch's with X-mas tree branches. I recovered them for the freeze. I did do anything to my Palace Purple (I keep hoping it will die). It is surrounded by lamium, so maybe that provided some protection for it. I also have Amethyst Mist, Raspberry Ice and Lime Rickey and Heucherella Burnished Bronze and Sunspot. Last season I had moved the Lime Rickeys and 1 ea of the Heuchs. Everything else is more established.

Mine did worse this year than they have before. I think it was the particularly odd weather, as oldroser said. I don't think the hardiness zones accurately reflect weather that involves freezing in October, a warm December, and single-digit temps in February. The horticulturalists are going to have to start developing an index that measures the tolerance for climate volatility!

Nil