Update on some crosses I made in 2017. These were planted in the ground in July 2018 last year & all had developed powdery mildew in the fall. They were heavily mulched with straw, temperatures dipping down to the -30s C during February. I am curious if they will get powdery mildew again this fall, I read sometimes they can grow out of it. These are my survivors:
Snow Pavement x Michel Trudeau
Snow Pavement x Wasagaming
Snow Pavement x Prairie Peace
Snow Pavement x double yellow scotch (ID to be determined, comes from Olds College - rose is a few steps west of Prairie Peace)
Snow Pavement x Roseraie de L’Hay
Snow Pavement x Prairie Dawn
Snow Pavement x Therese Bugnet
Snow Pavement x Suzanne
Snow Pavement x Marie Bugnet
Snow Pavement x Scarlet Pavement
Snow Pavement x Metis
Snow Pavement x Minette
Wasagaming x Scarlet Pavement
Wasagaming x Michel Trudeau
Wasagaming x Marie Bugnet
Wasagaming x double yellow scotch
Wasagaming x Snow Pavement
Wasagaming x Blanc de Double Coubert
Wasagaming x Therese Bugnet
Wasagaming x Suzanne
Wasagaming x Prairie Peace
I confirm Wasagaming is a difficult seed parent. Many crosses I repeated many times before a hip would set. In many cases, only half the hip would develop, or hips would swell and later fall off. Last year, I did not do any pollinations and no hips were observed on Wasagaming.
I found it interesting the number of seeds does not always relate to the number of germinations. For example, with Wasagaming x Suzanne I had hundreds of seeds, yet only 2 germinations. With Wasagaming x Michel Trudeau I had only 9 seeds collected from several hips, yet all 9 seeds germinated. I wonder in both cases could this be the result of cross-contamination, or self-pollination. I suppose only time will tell.
Wasagaming x Therese Bugnet and Wasagaming x Marie Bugnet had lots of germinations, and I am seeing some second-year germinations.
This year I hope to try some more tetraploid pollen with Snow Pavement, perhaps to get a rugosa hybrid something like Polaries. The cross Snow Pavement x Snow Pavement (5 attempted hips using pollen from a different bush) was unsuccessful for me, so I think Snow Pavement may be self-sterile.
I love your crosses Roselynn! We got to -33F in the Twin Cities this past winter and more newer cane hardy rugosa rose hybrids would sure be great. Here ‘Snow Pavement’ gets mildew too, but not super bad. I sure love the silvery lavender color. It’ll be exciting when more and more of your hybrids bloom. I’ve just worked with rugosas a little bit. It seems like patience with them to start blooming is a good thing as they seem to have a longer juvenility period than other roses. It may take 2 years for some to start blooming, but then those that repeat well will do so consistently. I agree with your assessment that ‘Snow Pavement’ is self incompatible. In isolated landscapes it doesn’t set seed here, but with other rugosas around it does. It seems that self incompatibility is pretty widespread in rugosas. Some people have argued with me about that assessment before, but I don’t think they recognize that self incompatibility is a continuum in terms of degree of expression and recognizing the factors that impact expression. In roses, the pollen from “incompatible” pollen germinates, but then grows much more slowly down the style and often gets stuck due to protein interactions/recognition. When there are warmer temps that seems to reduce the effectiveness of those proteins allowing self pollen to make it further and more readily lead to some self fertilizations. Those of us that are in colder climates I think can benefit from self-incompatiblity more in roses that possesses it in that a higher rate of the op seedlings we gather are from natural hybridizations.
David, I think I’m going to try keeping some rugosas in pots in the greenhouse for use as seed parents. Hopefully the higher temps in the greenhouse will allow more of the pollen that I apply get through and set seed. Hansa has never that I remember set hips in the ground here, so I might pollinate a potted one and place it in a 90-100 degree greenhouse environment for the day to see if it can form hips. Above & Beyond sure responded well to greenhouse pollination last year.
That sounds really cool Joe!!! Thank you for the great idea!!! I have one A&B rose in a pot and should try that. It is usually just a good male. That is great higher temperatures may help with overcoming more than just some of the typical self-incompatibility limitations.
self incompatibility is a continuum in terms of degree of expression and recognizing the factors that impact expression. In roses, the pollen from “incompatible” pollen germinates, but then grows much more slowly down the style and often gets stuck due to protein interactions/recognition. When there are warmer temps that seems to reduce the effectiveness of those proteins allowing self pollen to make it further and more readily lead to some self fertilizations. Those of us that are in colder climates I think can benefit from self-incompatiblity more in roses that possesses it in that a higher rate of the op seedlings we gather are from natural hybridizations.
David, thank you for the info on the effect of temperature on self pollinations & self-incompatibility. This would explain the conflicting information I have read on rugosas. Many times I’ve read that rugosas easily self pollinate, but I haven’t seen that in my garden.
Snow Pavement/Schneekoppe is a lovely rose, in addition to it’s unique colour & fragrance, the hips are very tasty. I’ve seen some Snow Pavement plants with better & larger bloom form, not sure if this is due to maturity, temperature, or other factor. I couldn’t’ find too much info on this forum on the use of Snow Pavement in breeding, but it’s good to see some more offspring from it listed on HelpMeFind such as ‘ΣL2a’ & ‘Haroxa’:
Mildew sweeps through my garden on some years (where even the dandelions get mildew), but I’m fortunate - most years I have very little disease pressure.
Joe, I’m curious as well if Hansa will set hips for you potted in a greenhouse. The fragrance on Hansa is amazing!
curious how your Wasagaming seedlings are doing. Glad to hear it at least accepts some pollen, although I think I will test its pollen more extensively. Surprised to see it accepts Campfire, although obviously pleased. Any updates on any of these seedlings?
Three juvenile bloomers in the Snow Pavement seedlings, but none on the Wasagaming seedlings. Of these three bloomers, two have rugose foliage, and one has smoother leaves. The first blooms were a bit distorted, so I shall hold onto them until next year and see how they do.
Overall it’s become a crowded space & I’m not sure where to go with all them. Photos attached from this summer.
beautiful growth on some of those! Space certainly becomes an issue. Really good to know about juvenile bloomers from Snow Pavement. I have only had one Juvenile bloomer in cold hardy and that was from Therese Bugnet.
Thanks for the update. Good luck with those!
HI- re Wasag x Campfire-
Ended up with maybe 18 seedlings, all scrawny and mildewy, none reblooming. Culled them all. May try again next year. Did get one juv. blooming seedling of Easy Going x Wasagaming but am not entirely convinced that Wasag is the daddy. Flower says maybe, leaves say not so much. Kept that one to assess next year.
donald, thanks for the upate! Sorry to hear about wasag x campfire, seems like a lot of potential in that cross, if only the genes would agree.
Good to hear about Easy Going x Wasag. Look forward to hearing about it next year.
Adding to this topic as I have just harvested five OP hips from Snow Pavement.
Not sure how long they were on, but at least 85 days, since that’s when I also made some pollinations on it when I noticed it was setting hips (it had previously refused to). The hips were fully ripe and starting to get mushy.
This was in the middle of a heatwave so the heat may have weakened SP’s self incompatibility. If not, roses blooming nearby at the time were all HT’s and floribunda/ shrub types (Angele Pernet, Julia Child, Orienta Aylin and a White Queen Elizabeth seedling).
I only left five hips on although it was setting way more, because I thought “what would I even do with that much OP seed”.
Well, I could have left them all on, because the number of seeds per hip turned out to be very low, between 2-8, runts included. I’ll post here in a few months if any of them germinate.