Check out the site below.

Here is a link that might be useful: Daylilies on Ice

Here is a list that I refer to a lot:

Here is a link that might be useful: Hardy Daylily Evergreen Poll

Evergreens shown to be hardy in northern areas, as listed by people in an online daylily I belong to:

This list was posted by someone in zone 5 --
ABSOLUTE TREASURE
BREAKFAST AT TIFFANY'S
CORAL CAY
CRYSTAL SEA
EASY NED
EMPEROR'S DRAGON
FORSYTH LEMON DROP
JASON SALTER
LOLLAPALOOSA
LONG STOCKING
MOROCCAN SUMMER
NAVY BLUES
PALACE GARDEN BEAUTY
SPACECOAST SWEETNESS
TWENTY TWENTY

These were reported to have survived their first winter in a garden in Maine (whether a future winter will do them in....who knows?) --

ABILENE NAN
AZURE WINGS
CANDIED POPCORN PERFECTION
DAKAR
ETOSHA
FASHION LEADER
PURPLE PEOPLE EATER
SKEEZIX

I've got many, many names of other daylilies that have done well up north, but I've not noted whether they're ev's or not.

Hope this helps!

Thank you all for your very welcome assistance. I will look these over. Gotta try some.

Here is a list of the Hardiest Daylilies for the North from the Far North Forum. It doesn't differentiate according to foliage type at all; but if there's one that you're interested in, you can see if others are growing it.

There are actually a fair number of threads about daylilies over there - especially in the gallery. The pictures aren't generally of the newest and fanciest varieties (for real eye candy, come here!), but they can give you a good idea of what is hardy.

Here is a link that might be useful: Far North Forum - Hardiest Daylilies for the North?

Evergreens for Zone 3 or 4?

That was the topic question and title.. if I am not mistaken. 3 and 4 can be.. are a DIFFERENT world... from what the many experience south. Like the north pole vs the equator.....

First qualifier: SNOW cover.. as in when and how much. If early before a penetrating freeze.. you get NO real cold hardiness testing.. IF.. said snow remains thorough the winter. Our current snow depth now is well over 16" on the level.. over 50" for the season.. starting before said hard freeze up. Ground temps now are around 30F at crown depth.. say 1-2" below ground surface. So.. many far north can get many things to survive.. most often not THRIVE..So.. a USDA zonal map can meaning nothing per hardiness issues..given weather patterns.. snow cover et al.

I said.. 'most often not THRIVE'.. goes to warmth in the growing season. Growing Degree Days.. one agricultural method of indexing summer warmth.. aka GDD's... shows many far northern regions lacking in the warmth required to make southern genetics.. mostly Ev's really show well. This sans a GH.. sans southern locations on a building for an ideal location.. those kind of games aren't proving northern hardiness. .

In my reference frame.. there's two kinds of plant habit.. dormant.. and everything else. True dorms go down before a real hard freeze up (late Oct thru Nov here).. setting resting buds below the soil surface. Southern dormants are really just 'photo' dorms.. setting their cycle on sunlight. Dormant does NOT mean cold hardy north.. unless said plant is tested under REAL cold temperatures.. that being SOIL temp the crown is exposed to..From my research and on-site experience.. for every true hardy ev north.. there's tons of dormants that are truly hardy. This means tested under the thawing conditions of a mid winter warmth.. the numerous freeze/thaw cycles often seen via the winter and the final arrival of summer.. usually around the 1st of July.. :).

So in the end.. only one's on-site culture is the real test of a plant's hardiness for the far north. The many are fudging on this cold hardiness issue now.. to sell plants to the newbies. Whatever.. but a compost pile doesn't cost much.

Northerndaylily,
I appreciate the synopsis. Our snow cover can come late and not accumulate to a great depth. Once the snow comes, it tends to stay, even through the odd January thaw. Most winters, we have a total of about 12", greater under drifts.
We are relatively new to daylily growing. We have about 20 plants right now, about evenly mixed between dormants and semievergreens. All of these are thriving nicely. I had looked at a number of evergreens, but was holding off on a purchase until I heard from someone with experience. There are a lot of very nice dormants out there and my experience thus far with semis leads me to experiment there.
From what you say, it's probably better to stay away from the evs.
Thanks.

Temps reading today.. Jan 14th.. at crown depth.. 1-2" down.

Under the snow.. 30.5F

On the path on the north side of the house.. 2' wide shoveled.. 16.5F

16.5 F is about -9 C. That is our normal high at this time of year. Before Christmas we went through a stretch of -25C temps (about -13F). Those were the highs during the day. At night it would plunge to close to -35 or -40. Also normal for a stretch or two like that in winter. Four or 5 years ago we had a week of -55C temps (about -67F). Those were the highs during the day. That was not fun. During that week a friend of mine had a job interview via phone with some people in Florida. While chatting one of the Florida group asked my friend what it was like up here, to which my friend replied that it was -55C. There was silence for a while, then my friend asked if they were still there. "Yeah, we're here. We're just trying to wrap our minds around -55 temperatures!"
What kind of thermometer do you use to take ground temps?

I use a common meat therm.. digital.. bore the hole with a portable hand drill.

Amazing how soil temps change.. per sunlight.. types of mulch.. et al.

Daylily hardiness is also really tested in the spring.. per freeze/thaw cycles. Dormants then really shine.. worst conditions for the ev flavors of daylilies.

-26F here this morning.. Jan 16th. Means nothing per the daylilies.. as again their sleeping under this thick blanket of white. Snowcover hasn't been the norm here in Central Wisconsin for some time.. now the last 2-3 yrs the cover has been deep and relatively early in coming. Open winters.. barren of snow cover with frigid air is the killer of all garden plants. Not one's location on some USDA map.........

Soil temp is 2F.. at crown level.. on shoveled path 2' wide.. northside of house on Jan 16th 1PM.