Rosa acicularis

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Paul G Olsen

Re: Rosa acicularis

Post: # 11385Post Paul G Olsen
Fri May 18, 2007 1:00 am

I now have 'Hansa' x Rosa acicularis 'Kinistino' seeds that have germinated. Actually, it's the second or third time I've achieved this. Because I don't have a good environment to grow my rose seedlings, I've lost them in the past at the small seedling stage. This year I delayed germination, so I could set the pots containing my seedlings directly outdoors. I planted the seed directly in the pots and kept them in the fridge until they were ready to germinate. I have found this method produces healthier and stockier seedlings compared to planting seedlings germinated in poly bags. There is also much less loss of newly germinated seeds. This may be a routine method in warm climates but it's not in cold climates.

I also have Rosa woodsii x 'Hazeldean' and Rosa woodsii x Rosa acicularis 'Kinistino' seedlings. The former should produce bicolours and the latter should be tetraploid. As far as I know, no one except perhaps Erlanson has done the latter cross before and produced progeny. And that was decades ago.

Paul Geurts

Re: Rosa acicularis

Post: # 11391Post Paul Geurts
Sat May 19, 2007 1:00 am

Paul,

I too, germinate my seedlings in plastic bags. I had many more seeds where the seed coat opened up than I had that actually developed into seedlings. I found that I was I a little too eager at first because I was planting the seeds before the root tip emerged from the seed. When I became more patent and waited for the root tip to emerge, I had much better germination rates. I had seeds from one mother where a high percentage of the seeds never produced a root tip at all, only the cotyledons came out. Needless to say those seeds didn

Roger Mitchell

Re: Rosa acicularis

Post: # 11405Post Roger Mitchell
Sun May 20, 2007 1:00 am

Jerry: I have some R. woodsii x R. acicularis hybrids from a few years ago that have bloomed. The problem is that I used clones of R. acicularis that I was able to mail-order in the U.S., and may actually be R. woodsii themselves. I originally obtained R. acicularis 'Aurora' from Greenmantle just to be sure I had the genuine article. I ended up using a clone I got from High Country Roses to make the R. woodsii x R. acicularis cross. Now that I have grown some genuine R. acicularis, I suspect that the High Country clone may also be genuine. It has the very early, larger bloom, the bushier form, and the much larger leaves of the real R. acicularis (compared with R. woodsii). I will have to try the pollen from these plants this year. I am going to attempt to get a rough idea of ploidly by examining the pollen size first.

Relative to your seedlings, I have found that this kind of cross naturally produces high early seedling mortality. The key seems to be to grow enough to get survivors.

Jerry is correct that R. acicularis 'Aurora' is exceptionally beautiful. Not only does it have a nice bush and unusually dark flower, but it also has exceptionally fine foliage which is large and dark green, with a very distinctive blue tint. I have crossed it with R. blanda, aiming to get unbalanced tetraploids that might have some fertility with modern roses (like the R. woodsii x R. acicularis crosses). This year, I am also going to try a similar cross with R. rugosa. Because of the foliage color, I also am going to try to cross 'Aurora' to R. glauca. I have seedlings growing of R. glauca X R. blanda, so that should be possible.

Even if R. acicularis were the ugliest rose in the world, its winter hardiness would make it desirable for hybridization. The challenge is the chromosome number, of course.

The main Eurasian form of R. acicularis is said to be tetraploid, which makes me wonder how it would do for breeding. I wonder if it would share the tendency of R. laxa, R. fedschenkoana, and 'Ross Rambler,' (all Asian tetraploids) to loose flower buds in the late spring freezes that I get in my location? None of the Canadian forms of R. acicularis I have grown ever loose buds, even though they are amongst the earliest-blooming of all roses. Since 'Pike's Peak' was bred in the United Kingdom by Gunter (1940) (source: HelpMeFind.com), I have wondered if its parent was the tetraploid R. acicularis that apparently has been introduced in to the U.K. from Scandinavia. That would make 'Dornr

Rosarian_Du_Nord
Posts: 21
Joined: Tue Nov 14, 2017 1:17 pm

Re: Rosa acicularis

Post: # 73530Post Rosarian_Du_Nord
Wed Dec 01, 2021 5:00 pm

Hi David!

What has become of your plant of Joan's 6x R. woodsii after all of these years?

Tony

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