Polstjarnan seeds

Has anybody had any sucess in germinationing seeds from Polstjarnan? I collected several seed pods and ended up with about 20 seeds. I think the seeds are probably OP, although it is growing near several hardy species roses.

My sucess rate in germinating seeds was a little better than last year and right now I have the seeds in a damp paper towel in the frig. Any suggestions on improving the germination rate as I would really like to get some seedlings from Polstjarnan.

Hi Ross!!

That is awesome you have so many seeds!!! Out of all the thousands of flowers on Polstjarnan I only remember one op hip forming with one seed that didn’t germinate. I hope you get some great offspring! It would be wonderful if some segregate to be repeat bloomers.

Hi David

From what I’ve read Polstjarnan is difficult to get seeds from. That’s why I asked for suggestions on germinationg these seeds. I would really like to post the results next spring. Perhaps next spring you will stop by on your way to Rosemount.

Lastly, I saw a picture of your new rose in the lastest ARS. Very vivid color.

Hi Ross!

That’s a great question about germination. I have some R. begg. seeds now that I’m wondering for as well. For polyantha roses I’ve learned that in general (as with R. multiflora) that if I keep them too close to freezing they don’t like it and tend to rot. When I had them at 45-50F or so they started germinating within a month in moist peat!! For shrub roses or other generally hardy species they don’t mind being just above freezing at about 38 or 40F. I wonder if R. begg. would benefit from a warm stratification period before cold like some other hardy species. The polys don’t need it or seem to respond to warm strat. With Polstj. being a cross of R. begg. and a poly I don’t know what would be best. I would hope that it would tolerate cooler temps. well. I would lean towards warm strat in moist peat for a few weeks and then somewhere about 45F until some start germinating. A lot of the Cinnomomeae section roses seem to benefit from warm strat.

Just some ideas…

Thanks for the kind words about Candy Oh! Vivid Red. I look forward to stopping out Ross hopefully next year to see your roses and rabbits.

Hi Ross,

I just checked my R. begg. seeds that I have at room temperature and 5 germinated!!! They were extracted and put in peat on August 10!! I’m really surprised they have low seed dormancy perhaps like Synstylae section roses. It definatly has short styles and probably isn’t related to Synstylae section roses (it supposed to be section Cinnamomeae renamed section Rosa) even though the small blooms in clusters and more petite foliage and ready crosses with polyanthas makes me wonder. Most of the Cinnamomeae section roses I worked with have relatively strong seed dormancy. I would be even more inclined to treat your Polstjarnan seeds more like polyanta / Rosa multiflora seeds with a little warmer than typical cold period.

Take Care,

David

Ross,

I note my ‘Polstjarnan’ shrub is rarely visited by bees, so it may be that the hips were the result of self-pollinated flowers. Regardless, if you get seeds to germinate the results should be interesting. I did a few controlled crosses of this cultivar this year. Nothing took.

David,

I’m very surprised you got Rosa beggeriana seeds to germinate so quickly. I’ll have to experiment to see if I can get similar results.

Last summer I finally decided to give Polstjarnan (which is next to infertile and rarely produces op hips in my garden) a try and pollinated two sprays with Applejack. I didn’t bother to emasculate the tiny flowers because of the lack of op and apparently sp hips. The pollination clearly did something because those two sprays gave about a dozen of hips and a few dozen seeds, whereas non-pollinated again nothing. Looking forward to germination season. I think Polstjarnan X Applejack could be a very interesting hybrid.
Bw,
Jukka
Helsinki/Finland

Last week I extracted embryos from Polstjarnan seeds collected in 2014. The cotyledons are greening up on about six of them. Several years ago, I had some germinate using normal stratification. I don’t think I have any of the seedlings now.

Hi jukka,
With your valuable imformation on growing roses in Finland in mind.
I have another question for you. Here you mentioned using Applejack.Can you give us some indication how the Buck Roses perform in your environment?
Thank you,
Chuckp

Chuckp,
Buck’s roses are very poorly available in Europe. Applejack is the only one I have ever seen imported in Finland. Finding even Applejack in a bulk garden center here was a big surprise to me. I have mine still in a pot for hybridization, but I presume it will be hardy in southern Finland. Other than that I only have Prairie Star, which seems to have the (poor) vigor and hardiness of a standard bedding rose.
Jukka