Harsher conditions, whether they be extreme temperatures or increased disease pressure, offer greater opportunity to differentiate the good from the best. Not many Hulthemias have blotches that exhibit good heat stability, but there are some.
Jim Sproul
Link: sproulroses.blogspot.com/2011/07/hulthemia-holy-grail-blotch-heat.html
Jim, how many 100 degree days have you had? How much rain? Are your roses in full sun or do they get some shade?
I am so looking forwarded to adding your Eyeconic roses to my garden. I bought two Persian Sunsets this spring but only got one bloom. Did not get any hips from the pollen I used from it, but weatherwise it has been a horrific year here.
Hoping for better weather next year.
Howdy Jim
Thought I might throw my two bob’s worth in. I was researching on the net a while ago and saw where some one which I cannot recall now, crossed Hulthemia hybrids with blooms carrying large white eyes, it seemed that the white eye didn’t effect of the characteristics of the blotch.The blotch seemed to imprinted over it.
This photograph is sort of an example, though I think the colours would be to strong, but its white eye is quite big with streaking radiating outwards.
What are your thoughts on this Jim
cheers Warren
Back again , would be good if I put the photograph in.
Hi Joan,
Counting today, we have had 28 days 95
Some gorgeous seedlings there, Jim!
I think I’ll pick up a few of your EL’s and try to breed in some hardiness. The cool temps up here in MN might be good for the blotches, though I won’t be able to select for heat tolerance.
Joe
Thinking of the hulthemias as a hot desert rose, I was a little surprised to read of splotch fading, but then I suppose the non-recurrent species blooms in a cooler season.
I wonder where, genetically, the fading vs. stability aspect comes from… (Then again, knowing your extensive pedigrees, I suppose we’ll never know! LOL.)
Very impressive work, as I’ve said before.
And for the record Jim, when I google hulthemia, on my search, sproulrosesbydesign comes up first!
He paid extra for that! LOL!
The blotch fades in the hybrids, so it’s likely due to the fade characteristic in modern roses, not Hulthemia. Even though it’s expressed, it’s extremely modified by these genes. None of the close hybrids I’ve grown lose their blotch in either fading or higher heat. Kim
Not to mention three of the first four sites listed by Google for “hulthemia” are Sproul sites.
Hi Joe, cool summer nights should be “just the ticket” for enjoying the Hulthemias to their maximum! Cold hardiness is something I haven’t been able to select for, but I’ll leave that to those of you braving those cold winters. 
Hi Philip, I think that you are right that the non-remontant Hulthemia persica species does what it needs to in the cooler spring and earlier summer weather, so blotch fade would not be a factor. It would be interesting however, to expose developing species flower buds to higher nighttime temperatures to see what happens. That’s cool to hear about Google - thanks Philip and Kathy!
Hi Kim, my experience has been different from yours. All of the closer hybrids (Mr. Ralph Moore’s, Chris Warner’s) including my own, have shown diminution of blotch size and less intense blotch color saturation in warmer nighttime summer weather. As you know, most of these only bloom sporadicly during the summer (or not at all) following their very nice spring bloom displays. Probably Mr. Moore’s best for prolonged blooming into the summertime is “Tigris 2”. That one has an excellent blotch in the spring, but badly fades in the heat for me. The fade on these isn’t as bad as on many of the more distant hybrids, but is significant nonetheless in our climate. “N192-1”, the second from the bottom on the blog post referenced in this thread has been the best distant hybrid for me so far.
Jim Sproul
You could maybe make a climate chamber using COOL BOT tech. Down to low 30’s.
Jim’s Eyeconic Pink Lemonade is winter hardy zone 6. It survived our Pennsylvania winter. We will know next year about the other seedlings.
Jacques, up here in zone 3 we stop counting at zone 5. To us, anything warmer is an exotic tropical place where the old folks go to escape winter and where people wear sunglasses even when they’re not driving.
Thanks for the laugh, Joe! From the "land of endless summer! Kim
Nice and well understood, Joe. But if you think Pennsylvania is an exotic tropical place, I think a lot of people will beg to disagree…
(Although it may feel this way from June to September)
With our warmer weather last week, there was another “opportunity” to see how some of the blotches performed in the heat. “O343” looks to have done well.
E. Lemonade seemed to love the hot days here. I put Rosa virginiana on it because… why not? lol
We’ve had relatively hot most of the past month. Now we are in a 100 + cycle projected to last at least 10 days more. I/L has a blotch not even half the length of the stamens, but those are still bright red in the filaments. G34 has an "invisible " blotch these days. Trying a diversity of pollen donors like Peachy Creeper, Paprika, Strawberry Crush which may have some Hulthemia genes back there somewhere if tales are to be believed.
We had mainly below 30 Celsius last summer (Dec 2011 - Feb 2012), just one or two short lived 40 / 40+ Celsius days that entire summer if memory serves me right. Eyes For You showed a totally heat stable blotch in those conditions, including during the 40+ Celsius brief spells.
Mind…humidity here is usually way over 50% in summer.