Joan’s analysis in the following thread discusses the chromosome behaviour in light of recent research.
http://www.rosehybridizers.org/forum/message.php?topid=6268#6269
Link: www.rosehybridizers.org/forum/message.php?topid=6268#6269
Hi!
Thinking of health I would also tend to rugosas as partners in a crossing with Rosa glauca.
But thinking of something that has aspects of health and odour and fine beauty perhaps an interesting plant could be one like “Gruss an Aachen”.
I did some crossings with Rosa multibracteata and Gruss an Aachen this year, I don’tknow, if they will be successful.
I think it should be triploid, referring to literature, so fertility might be lower, but there could be both, diploid and monoploid gametes.
So, glauca could even behave in odd ways - something should fit hence. 
Greetings,
Arno
Rob B. I’ll save you hips. Please remind me in the fall.
Robert R. I’m high desert, so I wouldn’t think your enviroment was preventing good color. My pendulina seedling is darker than the one you pictured. Would you like a start of my pendulina seedling too? (Please send me your mailing address.) Also, while I have not kept it, I had another glauca x GC seedling with lighter foilage color (simular to your picture of the pendulina seeding). That seedling only set a few hips on the entire plant.
As far as ploidy, I’d GUESS tetraploid on the GC seedling and pentaploid on the pendulina seedling, but that is based on the (presumed) ploidy of the pollen parnts.
Hi Joan, you sent me several germinated glauca x pendulina seedlings and I never separated them.
Only one is pictured at HMF. The blossoms of the individual seedlings are slightly different from one another.
They are still all grouped together. None are particularly blue to my eye. I have a friend that grows glauca here and it seems much bluer not that I’m complaining!
I’m thrilled to get fertility. They do behave like tetraploids, at least as pollen parents.
I’ll send my address. Thanks!
I find that both Carmenetta and Louis Riel are not very fertile as seed parents. When left to self pollenate they will produce a rare hip or two. If you wanted to use them in breeding I would advise using them as pollen parents on something that is large flowered ,very floriferous, and very fertile, such as Prairie Princess or Morden Centennial.
Someone once told me that when crossing with pure species that the offspring will most likely resemble the species parent. When crossing with primary hybrids, that mix of genes will allow far more variation in the offspring. I think it would be far more rewarding to do the crosses with the glauca hybrids that already exist than crossing with pure R. glauca.
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Joan,
Thank you very much for the offer. I will, as you asked, remind you in the fall and I look forward to seeing what comes of any seeds. Do the glauca x GC canes root fairly easily? If so and you have enough plant material to part with some, I’d like to try my hand at getting some to root if possible. Thank you again for the offer of seeds.
An update on the fertility of ‘Isabella Preston’ (Rosa glauca x ‘James Mason’). All crosses with ‘Louis Riel’ apparently have taken and most if not all the flowers (maybe 20 or so) have set hips. So it appears this hybrid also self-pollinates quite well. Whether the seeds germinate well or not, of course, remains to be seen. Next year I should do a cross with ‘Carmenetta’ to see how that one would work.
Is ‘Sir Cedric Morris’ (Rosa glauca hybrid Rambler) available in the States? Regardless, maybe it is from Hortico who ship to the U.S. Another Rosa glauca hybrid that could be used in a breeding program to develop roses with glaucous foliage.
Paul,
Vintage Gardens lists Sir Cedric Morris as available by custom root. Although HMF doesn’t list SCM’s pollen parent VG lists it as R. mulliganii. It describes the leaves of SCM as “pewter toned, a sort of olive drab dusted gray.”
I have seeds in the fridge from 'Bella Nitida x R. glauca that I’m hoping will germinate. Looking for smaller plant with the glauca leaves. I can’t figure out if they do germinate what the ploidy count would be. Any advice on that?
Diploid!
Nitida is diploid and glauca pollen is haploid (one chromosome set).
Progeny fertility will be to observe…
Thank you Pierre. If a crossed a diploid seedling of Bella Nitida x R. glauca back to R. glauca I should get tetraploid results? If the BNxG seedlings are fertile that is.
With a tetraploid glauca as the female and fertile BNxG pollen you will eventually get tetraploid progeny.
3 + 1 = 4.
Thank you again Pierre!
Hi you!
this is truely a nice and good crossing I think.
Perhaps it might be done more delicious:
What about crossing in a recurrent blooming partner like “Hazel de Rougetel”, or that same named “Corylus” ?
Its a good plant.
I planted it at a shady place, but at least two times it flowers even there.
After that you could cross in Rosa davidii. Would fit.
Greetings from Germany,
Arno
Hello Arno. Thank you for the advice. I’m not familiar with ‘Hazel de Rougetel’ but I do like ‘Corylus’ and think it would make a good match. I’ll have to research HdR.
‘Hazel Le Rougetel’ is the same rose as ‘Corylus’ - Hazel bred and named it somewhat opaquely for herself (Corylus being botanical Latin for the hazel or filbert). Unfortunately such Latin cultivar names - especially those officially possessed by another plant - are frowned upon (expressly forbidden if you care to follow the codes set out to regulate them), and ‘Hazel Le Rougetel’ does provide a perfectly nice and equally meaningful alternative name. It will probably be a hard sell since ‘Corylus’ is so popular as a name for the plant.
Cursorily going through all the posts, I don’t think anyone else suggested these species, but two glauca species crosses I’ve often thought about (though not having the plants) are:
R. fedtshenkoana, whose cool-colored ghostly foliage might make for some interesting foliated offspring, as well as having great hardiness, disease-resistance, and some recurrance.
R. Moyesii (i.e. Geranium) just seems like it could make a pretty cool offspring with deep wine-colored blooms perhaps?
Philip,
I like the crosses you mentioned. Do you know the ploidy of R. fedtshenkoana?
It’s a tetraploid, but I wouldn’t let that stop you from trying it anyway!
Thanks Stefan. I’ll add Fedtshenkoana to my list of parents to use with R. glauca. The foliage possibilities are very interesting. Thanks for mentioning this one Philip.
R.gluaca x R.fedtshenkoana is a cross that just recently came to mind for me as well. The offspring certainly would have interesting foliage. I think white flowers with purple foliage would be very striking.
There have been several crosses of R.glauca with tetraploids before, Louis Reil and Joan Monteith