Paul O. has mentioned that he thought Polstj

I have no practical experience with Polstj

I have Polstj

Hi David,

Thanks for the ploidy information, I’m always pleased to add another diploid to my list, and hear you go and pull two out of the hat. Can’t fault you

I suspected that Polstj

Isn’t it odd Ross Rambler is so hardy? I thought roses adpated to Northern climates tended to exhibit polyploidy?

I think one has to be careful if he/she has the true ‘Ross Rambler’. It was so rare at one time that I don’t think it could be 100% identifed when it began to be distributed as that cultivar. Even the shrub at the Indian Head, Saskatchewan PFRA Tree Nursery that appears to be ‘Ross Rambler’, since it is unlabelled cannot be absolutely identified as this cultivar. This is the location where ‘Ross Rambler’ was discovered. On the other hand, I find it interesting that David Z. has determined his ‘Ross Rambler’ to be a diploid. This would fit the speculation that ‘Ross Rambler’ is a selection of Rosa beggeriana, a diploid species.

I agree with Jinks, despite that ‘Polstjarnan’ has limited fertility both ways, it shouldn’t be given up to use in a breeding program. Especially to develop cold hardy Climbers. I still think the way to go is to cross it with Rosa acicularis to develop a very cold hardy tetraploid breeding line. If such a breeding line could be developed, I very much like the fact that Rosa multiflora in the parentage of ‘Polstjarnan’ would result in the potential to eventually produce progeny having clusters of many flowers.

Is Ross Rambler fully fertile?

I grew Polstjarnan for a few years. Few stamens and few op hips with few seeds. Gave up on it.


I am in France and bought my Polstjarnan last year from mail-order Danish company:



Paul, I think there is a reasonable degree of certainty that the plant we know today is Ross Rambler by process of elimination, no? Unless there is another rose that could even potentially have taken over its ID, and I can’t imagine what that might be.

Hi all

For those working on the tetraploid level Paul likely has good a point regarding the use of R. acicularis with Polstj

Not sure about shipping to the UK. I got Polstjarnan from Corn Hill Nursery in Canada. I was under the impression that Ashdown Roses is trying to propagate Ross Rambler for sale.

Jinks, you’re not alone… the diploid level is where my interest has been for quite some time, too. It sounds like we’re of much the same mind on the subject.

Unfortunately there isn’t even a domestic U.S. commercial source for Ross Rambler - I had to get mine from Joan as well - but perhaps in a while, as Steven says. Some roses just don’t cross the Atlantic that easily; I also have a “special” object of desire in Europe that I would die for, yet I wonder if I’ll ever see it in my own garden.

It will be interesting to see what growth characteristics Ross Rambler contributes to its offspring (being not a rambler at all, but a very tall shrub). Not many people are breeding for the large shrub market these days, it would seem.

I found Polstjarnan (Polestar) in stock at www.roguevalleyroses.com. They are based in Oregon. They did not mention on their website about shipping overseas.

My start of Ross Rambler came from the Morden Research Center in Canada, if that helps anyone. I really haven’t done much with it–or for that matter, much breeding at all in the last few years.