I recently moved to zone 3b/4a, and am finding that foliage categories for daylilies do not correspond to hardiness, although the NGA database has the hardiness tied to the foliage. Is there anywhere that lists where a specific named cultivar is hardy to....or a list of locations where people grow it?

Moved to Daylily forum where the experts can help you better.

I do not know of anywhere that accurate daylily cultivar cold hardiness is listed. You may be able to find some information about some daylily cultivars by searching the internet for each specific cultivar. You may also find some information here from members who grow specific cultivars and the zones in which they grow them.
There is a list on the internet (outdated now possibly) of some daylilies registered as evergreen that are hardy to zone 5. There may be other similar lists.

You can guess a very approximate hardiness by where each cultivar was hybridized. The further south the location the less winter hardy (on average) a cultivar may be. The further north a cultivar was hybridized the more winter hardy (on average) a cultivar may be.
You can adjust that approximate hardiness of a cultivar by looking at the location where its parents were hybridized, if that is available. If they were hybridized further south then the cultivar is likely to be less rather than more hardy than expected and vice versa if they were hybridized further north. If only one parent was hybridized further north (or south) then the adjustment would be less than if both parents were.

The more generations that the ancestry of a cultivar is southern-bred then most likely the more adapted it will be to milder/shorter winters. The more generations that the ancestry of a cultivar is northern-bred then the more likely it will be better adapted to longer/colder winters.

Those are the best generalizations that can be used when/if there are no measured objective measurements of cold hardiness (there are few if any such measurements for daylilies that I know of).

Yes it is unfortunate that the NGA database ties hardiness zones to foliage type because as you've discovered they are two separate things. I'm in USDA zone 4 and grow all types. Are you anywhere near Minneapolis? You might want to talk to/visit Karol Emmerich who is Zone 4 and doesn't limit her cultivars as to follage habit. Her website is here

http://springwoodgardens.com/w...

There are some more cold climate hybridizers listed here although I see two no longer appear to be in daylilies.

https://web.ncf.ca/ah748/ccdc....

I would also recommend Rob Laffin up in Maine for cold hardy daylilies

https://roblaffin24.wixsite.co...

Mike Grossmann located in MN, has a list of Z:4 hardy Daylilies.
https://www.northernlightsdayl...
There's another list that was posted not too long ago

Thanks all for the replies. I didn't realize I was starting a thread. I live a couple hours north of Emmerich's, and I have found the other MN breeders. I just like to look and see what else is out there. I have several SE's that have done well, and grow some zone 5 things that shouldn't grow here. I was hoping there was a list somewhere of where cultivars are grown successfully. Dave's Garden does that with some cultivars...people post it grows for me in zone 5a, and it is ticked off for that zone..
It would be nice if this database did likewise. Ditto with the reviews BTW. Lots of info out there but it all takes SOOOOO much digging. Kinda like snow....

I think a lot of the hardiness issue depends on if you have reliable snow cover or not. We tend to have the cold without the snow and can't grow things that people in colder areas can grow. I see Cassa on the LA growing things up in Canada year after year that are impossible here. You might be able to grow things there in Minnesota that I can't grow in Ohio, so that makes it much more difficult to lump things in one basket. I think soil type also has a big influence in what we can grow. My soil is sandy loam, but my friends have heavy clay. They have a harder time with some plants, and they are just a few miles away.

My suggestion is for you to try to visit other gardens in your area to get some idea of what might grow well there. We have such a diverse selection of daylilies for all areas. As for me, myself, I just normally buy whatever I like and take my chances.... but I usually avoid evergreen plants unless I am using them to make crosses with hardy ones. As I said, I think reliable snow cover is the key- unless you are mulching with something else. I normally don't mulch anything here.

Continuous relatively deep (10", 25 cm) snow cover is excellent insulation against the cold. January is apparently the coldest month on average for us, but we have not had continuous deep snow cover during January for many years and even before then it was rare. I have not noticed any losses in my daylilies that could be related to the presence or absence of continuus snow cover during January here.

In the past, there was often a suggestion made that daylilies that might be suspected to be somewhat cold tender should be planted as early as possible in the growing season. I think that is very important, but it may imply that areas with shorter growing seasons might have problems. I suspect that daylily losses of cultivars that are hybridized in locations with mild winters (and long growing seasons) may frequently happen the first year that they are planted in locations with more severe winter conditions (but if such cultivars survive their first winter after being purchased they usually survive their future winters). I think that there are cultivars that take a long time to acclimate to the weather conditions in their new locations with more severe winter conditions. I suspect that many of those cultivars need a longer growing period to properly prepare for winter after they have been dug and divided. I think that they often do not get sufficient growing time in their new locations and then die during their first winter or are badly damaged during their first winter. If they do survive, then their second growing season can be a repetition of their first because of the damage they may have sustained during their first winter mimicking the damage they sustained being dug and divided.
That is what I think happens here to 'Crystal Blue Persuasion'. I bought it several times over the years and it died each time, never surviving its first winter here. Then I bought it, potted it, kept it growing inside over what would have been its first winter. I then planted it outside in the spring, pot and all and left it over winter. It survived. I think this is also what has happened in the past to 'Enchanter's Spell' (ES). I now have ES growing successfully in a location outside here. One year I ran a simple test on it. I used a spade to cut through its roots, lifting it slightly while in the ground to make sure the roots were broken. I then firmed it back into the ground. The next spring it suffered considerable winterkill which it had not shown for years.
I remember reading many years ago that some particular plant species (e.g. Clematis?) did not "like" to have their roots disturbed. The only research I have found of similar effects is that newly planted ramets of Miscanthus differ in winter mortality from established, recently undisturbed ramets of the same cultivar in the same location. The researchers suggest that the disturbed plants do not prepare for over-wintering in time because of the effects of being divided and replanted (disturbed). Any plants that do manage to survive their first winter apparently have then produced/recovered an effective timetable for preparing for winter in their new location.

Yes, lots of good tips here. Snow is a good insulator, usually there is 2' on the level here all winter. We have heavy red clay, so we brought in truckloads of sand and good soil to make some slightly raised beds for perennials and a raised deer fenced veggie garden.

We are on a south facing slope to a lake, and protected to the north by a wooded ridge. I'm in my 70's now and my mom was quite a gardener....she always said you should plant in the spring for things to "get their roots down". More true here.

Interesting experiment with the daylily roots tho Admmad. Yes, some plants hate getting their roots disturbed and do not transplant well....oddly some plant don't like having their position relative to the sun changed either. Growing conditions matter.

I live in an area where there are surprisingly few gardens...it is rural here and if you can't eat it they just don't want to bother planting it. Minimal landscaping, if any.

I do have one southern bred EV that I planted here 3 years ago and it looks great. I planted it on our first bed on top of our new septic tank (not the drain field) Sounds weird, but an inground septic tank produces heat, so I figured that combined with the great soil they brought in for backfill and the snow, I could get away with it. We had 35 below zero last year, and it looked great this spring.

So I think my best choice is to just try and see what will grow. I do select mainly dormant cultivars, but won't rule out others if they are strong growers. Means I get to choose new plants if my first ones fail...and that is not always a bad thing.

I found the listing of zone 5 hardy evergreen daylilies from the Cottage in The Meadows blog. It would be nice to have this kind of list for general daylilies for zone 4...maybe I will start one. (As the blog is not active, I did make a copy for my files, if the blog post goes down you may contact me.) At any rate it may help others. Being new I couldn't post the link, but if you google zone 5 hardy evergreen daylilies it should come up.

To add one to the list, I'm picking up Wonderworld from Patrick Dooley of Dooley Gardens in Maine. He isn't coastal, I think he's at least zone 4 or 5 and he says it has done really well for him.

I will add it the list appears to have ended in Feb., 2018. Wonderworld is listed as a zone 5a in the database, but that is just the "evergreen" default. Very pretty. It is interesting that it is a more recent Stamile, I have read that they aren't as hardy as the older ones. The only EV's I have are Joan Senior and Entwined in the Vine...which have made it thru 3 winters here. The only Stamile I have is Night Embers and it is doing well, so far 3 winters, but it is an older one and it is SE. If anyone wants to add ANY zone 4 daylilies I will add them to a list (oh no another database!) and try to figure someplace to post it. I may have to join Facebook yet.

@adnative Dianne might have some good cultivar suggestions for you. She knows all about cold hardiness!

Thanks, will check.

This is an old one for zone 4:
The thread "USDA Zone 4 Favourite Daylilies" in Daylilies forum
I checked, but could not find a zone 3 equivalent.

Thanks I will check it out. I did find a list on another forum. There is also a Northern Wisconsin daylily FB page...but I am not on FB. I am trying to figure out zone 3/4 SEV's and EV's that are hardy.....you always want the ones you can't grow....

DeweyRooter said: @adnative Dianne might have some good cultivar suggestions for you. She knows all about cold hardiness!

Thanks for the vote of confidence, Nan, not sure I would claim to know 'all' But I have been growing daylilies here in zone 3 for nearly 30 years now, so I've had a bit of experience with some of them.

Over the years, I have only lost (2) daylilies that I believe were lost due to lack of hardiness for our chilly winters: Barbary Corsair, which did make it thru its first winter but went steadily downhill and disappeared by the 3rd year... and 'Little Mucha Minto' which did not make it the very first winter.

I have planted fall daylily orders from southern growers, with great survival of the daylilies (including a fall order in 2022 from Browns Ferry) ... keeping in mind, just about everyone is 'south' from here. But I mulch everything, plant all daylilies from warmer climates about an inch deeper than usual, and generally get my southern orders (Florida, Tennessee, etc.) no later than spring, they have time to acclimate. Most will not bloom till their 2nd year in the gardens, but patience pays off.

I do not believe foliage classifications have 'any' bearing on cold hardiness (I grow all, from Evergreen to fully dormant, with success); and I consider 'zone' listings as simply a suggestion (at best). Many 'zone 5' plants survive well here, including many daylilies... but again, I mulch everything. (And I do mean 'all' of my perennials, including shrubs.)

At this point (not counting roughly 2000 seedlings), I have over 400 registered daylilies that survive zone 3 very well. For what it's worth... I really don't pay much attention at all to where the plants are grown before arriving here, or where they were hybridized ... or their parents, either (some northern breeders use greenhouses, which negates zone). I pay attention to when, how and where I plant them, and I think that is far more important to their success.

Dianne, you are my hero!

@Deryll Oh, my goodness... Thank you.