R.glauca seedlings are powdey mildew resisant

Last fall I brought in several plants to over-winter in the basement under lights because I didn

My R. Glauca seedlings have been outside since early January

and although I have had a lot of PM on my other seedlings there were none whatsoever on R. Glauca seedlings. You are very correct, most of the seedlings look alike except I have three R. Glauca X Frontenac seedlings which are light green in color like Frontenac.




Glauca x pendulina will get just a touch of PM here at certain times of the year. Powdery Mildew is my arch nemesis so I notice such things.

I have not noted PM, yet, in GLPE offspring.

I should add that R.glauca x Frontenac is a very good cross. The seedlings should be very hardy. I’ll be interested to hear how they turn out.

I was just researching Frontenac this morning. I’m curious, what are your impressions of it.




Your work with GLPE is very encouraging. All of your seedlings look great, but in the photos, it looks like there is some R.glauca influence in the foliage of the CD x GLPE and RKO x GLPE seedlings. That would be great if it’s influece can still be seen in second generation seedlings.

Paul, I was trying to keep Frontenac a secret :slight_smile:. I believe someone else is using it, maybe David. Anyway it is my most disease resistant rose here on the humid Gulf Coast so I will use it as much as pollible. It is in its third year now so I will try to get some seeds from it. Last year late it set several hips and I have a couple of seedlings from it. These hips set real late and I collected the seeds in December so maybe in a normal season of ripening they would germinate better. The pollen I used from it seemed to be fertile on the roses I tried them on. It does bloom a lot with not much fragrance.


Frontenac!! Thank you Paul and Patrick, I may have just figured out what my Simon Fraser bush really is. Ever since I saw Mark Disero’s Simon Fraser last summer I have been questioning if mine is really Simon Fraser. The other photos in HMF look nothing like the 2 that I had loaded. Mine is extremely disease resistant, with huge dark pink blooms and good winter hardiness. It is an extremely good seed parent. Actually I put Henry’s Rugelda x R15 pollen on it last year and have a nice crop of seedlings coming along.


The R. glauca seedlings and R. arkansana seedlings here are the only ones that -didn’t- get whalloped by downy mildew. Almost makes me want to start concentrating on arkansana and woodsii (had some of these, died of cats, though).

That sounds like a great cross Liz. I still say you and I think much alike.

Hey, hey now Patrick, we

Paul, I disagree about Frontenac not blooming much. In fact that is one of the main reasons it does not grow too fast, it is using all of its energy to bloom. Here is what someone put in the comments section on HMF.

This is definately an outstanding disease resistant rose. I purchased 50+ roses this year and have had trouble with blackspot, mildew and rust on most of the other roses.[It has been unusually wet in Saskatchewan] Frontenac has had no signs of any of the diseases. This rose hasn’t stopped blooming and the color is a very vivid rosy pink. Pictures of this rose do not do it justice.

This sounds more like the rose I have. Hopefully all or most of its good traits will go into one of my Glauca X Frontenac seedlings, especially disease resistance.


Great minds, eh Robert??? Actually If anything comes out of that cross I’m not sure that I can take any credit.

Patrick, my bush is constantly in bloom too. It is one of the first to start blooming.



I don

I am using Frontenac heavily. Part of the reason was what David said a long time ago: It doesn


Is that true? The breeders at Morden selected roses that would die back so they wouldn

It’s interesting to read everyone’s experience and thoughts on ‘Frontenac’. We included it in the Northern EarthKind trials because of the added hardiness compared to ‘Carefree Beauty’ and the disease resistance and promise of really good rebloom (Dr. Svejda monitored repeat/continuous bloom of it through the season and reported this benefit in her HortScience article on it). It is very healthy indeed so far across the trials. We have a Texas and Kansas site to see how well adapted the Northern EK trial roses are in the South. That is great to learn in the Gulf Coast Patrick it does well.

That’s a great point Paul about dieback and regrowth. I really feel more and more that all these marginally hardy roses for the North are disappointing for people. In extra exposed areas they die. Otherwise they are die down to the ground- sometimes regrowing well sometimes suffering a lot of injury and barely surviving. Some marketers try to make it a positive saying treat them like a herbaceous perennial as it keeps them compact. I think that is just trying to make lemons out of lemonade. In public landscapes and the average gardeners yard the thorny dead canes look messy come spring and with how busy people are with chores, the dead may not get pruned off until a lot of new growth emerges and is intertwined and becomes damaged. This happens a lot in public areas where limited parks staff now are expected to care for more area.

I like the perspective of trying to breed more cane hardy roses and then if people choose to prune them to the ground they can, but if they don’t get to it or don’t want to the plant will grow and look pretty good on its own come spring and people eventually can get to doing some rejuvenation pruning which isn’t necessary every year. It seems hard to combine all the triats we are looking for and need to keep accessing relatively tender parents for some traits which seems necessary. There are some hardier and hardier roses out there which is nice. I guess step by step, little by little improvements are achieved. For instance, I really like ‘Sunrise Sunset’ and it is a groundcover in some ways like Flower Carpet Pink, but hardier for us up here and even more beautiful with some warm undertones to the flowers and larger flowers.

The hardiness of the Mordens have been disappointing to me. When I lived in Northern WI (zone 3) they were generally not zone 3 hardy. I think zone 3 hardiness is a bit of an exaggeration for them. I wonder if they justify saying zone 3 because Morden is zone 3. Since they have such good snow cover and insulation it seems, the crowns of these relatively short roses do not really experience zone 3 temperatures. In open areas in Northern Wisconsin and even here in zone 4 in MN they can completely die out or suffer very severe injury. This is a reason I want to focus on breeding roses with better cane hardiness. It is sad to hear people be disappointed loosing roses and giving up on rose growing after thinking a rose should be hardy to zone 3 and they are in zone 4 and it dies over winter and the idea roses are finicy is reinforced in their minds.

Just some thoughts.



I agree David; I would have expected roses that came from Canada to be hardier than the Mordens. I believe you are right, when the breeders at Morden didn

As I said in an old RHA newsletter article:

Foolish me!! I have been working under the assumption that unless specified winter hardy meant cane hardy. Svejda’s definition was based on percentage of dead wood following an Ottawa winter with no protection. I suspect that roses that died back to the crown did not last long in her program.

My first winter hardy roses were Svejda’s and when I started looking at Buck’s and the ones from Morden I was expecting something similar. I had chalked up the lack of winter hardiness possibility to differences in the types of winters that the roses were developed to survived. I never suspected that there was a different definition of what winter hardy meant.