Sowed 7 weeks ago only (Oct. 2), here is my first 2016-17 germination of R. rugosa Alba x Dr Harry Upshall among 10 seeds. A Rosa rugosa seedling without cold stratification, what does it occur? I have had this surprise this morning when I took a look at my seedlings that are in waiting, at room temperature, for their cold stratification in a few weeks. It is my first try with the pollen of Dr Upshall. I have used it also on 13 others varieties with only 5 positive results including this germination. Among four others, two are from my own seedlings: 12JBD (The Gift OP) (50 seeds) and 133S-1 (White Mountain OP) (33 seeds), and the last two are from Lac Majeau (33 seeds) and Geschwind’s Nordlandrose (19 seeds). I hope also, I will have some others germinations from all of these four?!
Andre
It is really interesting to see an early germination. Thanks for sharing the photo. I had forgotten that ‘Dr. Harry Upshall’ was from a cross with Persian Yellow. It might prove useful as a way to develop cold hardy yellow roses. Does your 133S-1 (White Mountain OP) act like a climber?
Thank you Margit, yes I have used it for possible yellow roses and for fragrance potential. Also, may be Liverpool Echo could contribute to remontance. The semi-double flower of my remontant 133S-1 has only three feet after two years grow. But I have two non-remontant five feet sibling, with simple flower. I intend to try some crosses next year on these two with Dr Harry Upshall.
I forgot to add my photo…here it is!
My 133S-1 is at right below the sibbling133S-2 and far from them, at left is mother plant White Mountain.
Is your White Mount the same as Mont Blanc (1985)?
Johannes,
I’m pretty sure Andre has White Mountains, not Mont Blanc.
It was the s at the end of mountains that caused me not to find it.
Looking at the references on HMF for White Mountains, it was interesting to find this:
RHA Newsletter 9(2): 6-7 (1978)
Rosa Rugosa Hybrids x Miniatures
Lyndon Lyon
Open pollinated seed of ‘White Mountains’ surprisingly gave me, among others, one very miniature everblooming plant which has since had such influence in miniaturizing our smallest roses. All of our miniature roses with flowers that turn green as they age, show this influence.
It seems like your 1335-1 is a similar OP…dwarf and everblooming.
Hi Johannes, it is my error I always forget the «s» on White Mountains I am sorry! And thank you Peter for the link!
Jbergeson, I have another seedling shorter than my 133S-1 and that probably could be correspond to the reference you quote concerning ‘White Mountains’ influence in miniaturizing. From an only one germination obtained from a cross of White Mountains x Roseraie de l’Haÿ, made in 2014, a miniature rose has begun to flower at the beginning of May 2015 and I have always seen flowers on it until end of October. This small plant is only, at the end of season, 5 inches height by 8 inches wide. I have tried some crosses on it last summer without success.
Andre, I love the above seedling White Mountains x Roseriae de l’hay. My hybridizing with WM is always spotty
and based on erratic flowering of WM in pot. This year I’m trying different. I planted WM in the ground.
I’m not certain it’ll survive my prairie climate.
Do you take your WM down from its trellis for the winter?
Chuckp
Hi Chuck, I also love this seedling with his red buds, and sadly, I have the same spotty problem with my White Mountains seedlings. Effectively I select the longest stems and lay down them for winter followed by a good summer flowering. I am sure you will see difference.
André
Thanks Andre,
I didn’t put my WM up on a trellis this summer. I’ll put a fence around WM to trap the snow.
My WM seedling is very up right. I put some schneewerg pollen on it this spring thanks to Paul Olsen.
The hips set was not very good, but I find even my seedling is sporadic from year to year with seed set.
Andre, have you tried rooting cuttings of any of your seedlings?
Chuckp
I don’t do any cutting of my seedlings Chuckp.
Here is follow up of my three months old R. rugosa alba x Dr Harry Upshall with his 6 inches in height. As you can see on the photo below, the stem has lots of spines like spinosissima. I suspect it is a Persian Yellow heritage…?! It will take minimum three others months to confirm my supposition when I can put the plant outside, after the four feet of snow, that we have still now, will be disappeared. When it will grow outside, I will have a better idea on what I could expect.
What a strong, healthy looking seedling, André! Keep us posted on its progress.
Betsy
With pleasure Betsy! Effectively it is a vigorous seedling and maybe (I hope!), I will see some flowers on the new lateral ramifications?! I also have observed some very small glands on stipules, petiole and folioles when I have enlarged some photos (below). I don’t know if it is frequent but it is the first time for me. Is there somebody who has already had some experience with this observation? Is that possible that it could be a sign for future fragrant foliage as Persian Yellow? Thank you in advance!
Waauw André,
a very nice and strong new rose! Wondering if it will be continously blooming.
I don’t know if the prickles have anything to do with the R.foetida influence…
Keep us updated! 
It’s just a guess, but I believe she might continously flowering, but maybe also not winterhard?
It seems the seed did not went into dormancy, so maybe the rose also will not want to go into dormancy during the winter…
very fascinating!
Dane
Thank you for your comments Dane. I cross my finger for continuous blooming. You are right concerning dormancy that this seedling did not has need, only warm treatment before germination. As you write, maybe it will not want to go into dormancy next winter. But I think that will be different when it will grow outside and I count on mother’s hardiness, time (and next winter) will tell us…?! The rest of seeds of this cross have had 11 weeks of cold treatment and they are now at room temperature since one week. I hope to be lucky and have some others germinations, among the rest of seeds, only 9! Then maybe that I will be able to compare if they grow, knowing that each seedling has its own characteristics.
André