I can start this off with a Stout Winner...

Hemerocallis 'Heavenly United We Stand' (Gossard, 2009) 2019 photo

I get *well* above the registered height (45 in) on CHERRY PEACOCK. I had to stand on a stool to photograph last year.


You can see it towering in the background of this photo

Does anyone know what the tallest registered daylily is? Asking for a friend of course. Lol

Getting airborne

Had a Rocket City that bloomed well over 5'9" last summer, in some new dirt from a farm that I had dumped in a swampy spot. Never got close to that anyplace else.

Dances with Snowflakes from Woodhenge Gardens at over 50" is the tallest so far. This was it's first spring in my garden.

According to the ADS data base, there is a daylily that was registered at 96 inches.

Highlight (Hamblin, 1951)
height 96 in.(244 cm), season La, Diploid, YL1: Yellow light self. (H. altissima × Hyperion)

Additional geeky details since I looked them up before I realized Frank already answered.

Tallest Tets:
80 inches Levitation (Powell_W), '05)
75 inches Bees Dr Stout (Downie, 2019)

Tallest Dip since 1951
78 inches Eli Murphy (Murphy_JP, '06)

The tallest ones in my garden are

Banana Smoothie (Registered at 64", but more normally in the 50's for me)


Mascara Snake (Registered at 57", and I think I've had some that tall. I know it gets pointed out that this plant's scapes can lay down if they get too tall and have too many blooms, so I tend to stake the taller scapes just in case they start getting any ideas.)

Sorry, I am on my phone and no photos. I got Dances with Giraffes last year, it did not reach the 60" it should, but just planted in the spring. I have Final Frontier a few years ago, gets taller than it is supposed to. I know it measured 44" one year.
So glad to see your photo of Heavenly United we Stand, Frank, I just got it in the fall. I got Mascara Snake too!
I had no idea there were such tall daylilies out there, always something to learn!

Cherry Peacock is so pretty. I keep saying I'm going to get Heavenly United We Stand and then I spot something else I need a tiny bit more

A few ...
The Levitating Ananuki reg. as 64". It's growing in a wet spot so gets a few inches taller.


Notify Ground Crew reg. at 72", easily all that. That's Joan Derifield in the bottom right of the image, reg at 35".


Chew Mailpouch Tobacco reg at 73". Borrowed image since it's newer and then I went and moved it fall 2018. Hope it likes the new spot!


Swallows in Flight reg at 58".


Up on the Roof reg 53", Great branching!


Think that's all of the ones I have over 50".

Found another one, Way Up There, a tall dark red with white midribs. It's registered at 60".

Here is my tallest, Autumn Minaret, pushing 6'.
Sherry

Al's Peach Tower--Listed at 59" with 7" flower, and it is every bit of that. Flowers are so heavy scape does need staking, but can i blame it? No! It's the tallest!



Love Song--Listed at 38", but blooms up to 42" for me. Flowers are Big, but held well by the strong scape.



Ashwood Dark Side---Listed as 40", but has not gotten past 38" here.


Buddy's String Bean--40" and gets to that height


Lightning Storm--40" sometimes a bit taller


Splish Splash--42" and very uniformly that height.



Strung Out--Blooms at 40" to 42" here in NC.

Here's Hemerocallis 'Navajo Pony' (Gossard, 2011) 2019 photo

registered at 45 inches tall...

Don't forget h. fulva 'Europa'

I LOVE tall daylilies and am always looking to acquire more. The taller and the bigger the bloom, the better. I'm not as fond of small blooms on tall scapes.
I don't always remember to take full shots of clumps. Here are some of the tall ones in my garden:

Panic in Detroit (registered as 40", much taller here)



Artillery Fire (44")



Amazing Adam (51")




Starman's Quest (40")



Carl's Folly (48", at least)



Isabelle Rose (59")



Ocean Depths (48")



Tidewater Elf (39" or more)



Luna (at least 40")



I'm not sure how many pictures I can post at a time so I will upload these and follow-up below with more.

Here are more:
Shuffle the Deck (52")




Pinhill Tall Goddess (45")



Liberty Banner (40")



Sky Dragon (61")




Purple Architecture (42")



Mico (44")



Venus's Fire (42")




Up and At 'Em (45")



Getting Airborne (56")



Red Kangaroo (47")



Tall Dark and Handsome (52")



Fire in the Penthouse (44")



Happy is the Heart (45")



Lullaby of Birdland (48")

All of my tall ones are new last year or coming this spring. I don't like tall ones, anything over 34" I consider high, but sometimes a pretty face gets me and I buy before I see the height. Maybe with these I will decide tall isn't so bad. Navajo Pony was on my want list until I saw the height so maybe it will go back on if these turn out ok. These are the ones over 40"

Arrogant Bastard 44"
Cleo 48" I've had for years didn't know it was registered this high. It has never gotten that high here either but it is a leaner/drooper
Gamma Galaxy 67"
Long John Silver 42" It has never gotten that high here either

coming in spring:

Barnegat Light 55"
Freaky People 43"
Heavens to Murgatroyd 52"
Ocean Spirit 40"

Awesome tall ones everyone. Celeste Purple Architecture just glows
One that was not mentioned which I do not have is Rognvaldursson a dip at 78"
Sears Tower : 65-70" here



The Cow Jumped Over The Moon : 72"



One Above you : 65" in the second year, Scheduled to be moved.


Autumn King : 62" and loaded.




Under The Wire : 53" late and gorgeous !


Sky King : 56" doing a piggy front.



Pack Hunter :50". Consistently above the four foot chain link fence


Panic In Detroit : 50" awesome plant.





Free Wheelin : above registered height. 41"


Robin's Future seedling