I was wondering is if anyone has had experience crossing these once more rebloomers like Suzanne, Rosa spinossisima altaica, Rosa beggeriana and so pass on a degree to the more reblooming like HT and still get rebloom
I am also curious if these fall bloomers are more climate sensitive since Southerners claim no rebloom yet my altaica is almost 1/4 of the spring show and beggeriana (a sucker) has put out 6 flowers.
I love seeing stray fall rebloom too on some of these roses. Vernalization is the cue that seems to allow flower induction to occur. From some of Andy Roberts and others work the concentration of a particular group of GAs seem to be low just at budbreak and that is when the growing point converts over to product flowers. Soon after the GA spikes and then continuous vegetative growth continues. In repeat flowering roses they seemed to have a consistently low GA concentration for the GAs followed and that seems to allow them to flower repeatedly.
I wonder if night time temperatures begin to allow some chilling hours to accumulate and maybe some interaction with photoperiod allows us to have stray repeat on some roses that typically are known to be spring only bloomers.
Are the reblooms on new wood? Or are they delayed buds from the past spring?
Down the road we have a set of 4 flowering crabapples growing in a very narrow space between sidewalk and street. Some fall seasons, such as this one, they put on a fairly abundant show of flowering. In their case I think that severe stress of a hot dry period, followed by cool rainy weather, is what induces the outburst.
David is right about vernalization being the usual control, but there may be more than one way to skin the cat, depending where the species comes from.
Dr Buck crossed Suzanne with Morning Stars and Carrousel to get Prairie Princess which became basis for most of his hybrids.
It would be good idea to cross Suzanne with healthy moderns to get something similar to Prairie Princess but healthier; we might start on that next yr.
As to re-bloom in colder climates (zone 3A Canada) was surprised this last weekend to see a 8-10 foot rose labeled Scotch Briar with a few blooms - yellow singles but color probably enhanced by it being cold and rainy in Calgary for nearly 2 weeks. Had a good crop of black hips also.
None of my Scotch roses or spinossisima’s have “re-bloomed” in 6 to 10years. My beggeriana hybrid? White Star of Finland has never re-bloomed in 10 years. My other nearly “once bloomers” only re-bloom on end of season new growth but more like a 1/10 of spring.
I wish I could have met Griffith Buck. I really adore some of his roses.
I plan on using his Summer Wind to its fullest. I have really fallen in love with it despite that its a pink near-single. Its a really smart cross that involves dwarfing traits and pelargonidin of the orange-red polyantha/rubiginosa lines, habit/repeat/architecture/tones/fragrance of the pernetiana-based FL/GR/HT lines and the grace, health and hardiness of Rosa laxa. I think it has a lot of potential as an F1 out of Applejack that has very modern traits. What I find peculiar is that there are very few F1’s from Applejack. The majority of breeding from the Applejack point has been in f2 and beyond. I like it better than Carefree Beauty because the tone is warm and I dont really want to breed anything with Carrousel immediately in it. I am sure of Summer Wind’s minimum hardiness but it does seem like a smart choice for further introducing warm, modern tones into cold hardy roses. I also find the scent to be intense, which was happy news for me because its very difficult to find roses to breed into floribundas/shrublets that still have any fragrance.
I should have tried Summer Wind x Golden Wings. Meh…too late now. That would definitely be a helpful type of cross for modern color, fall rebloom and winter hardiness for ya northern folks.
btw, for ya northern folk in terms of ideas, I am also growin Prairie Sunrise and Winter Sunset. The former is a healthier source of Sunsprite. The latter is a healthy source of pelargonidin and apricot tones. They make great plants and have great color/scent. They both do have some fade but its not really a big deal considering everyhting else they offer. They rebloom just as much as a floribunda would. Winter Sunset is a good example of an excellent rose that could be somewhat like a new prototype for the HT. It has stems long enough to cut, have good formal architecture, has good rebloom/scent/formal form but it is not overpowering in the garden. I would love to see HT types become more and more intuitive within the landscape. Not only would it look smart but it would also help retain rose popularity among the common public. I like Double Red Knock Out a lot specifically because the blooms look like small, red HTs. The color could be better but its a pretty awesome compromise of something that looks smart while still being friendly to the space it resides in.
By the way, whats the farthest north Rosa rubiginosa goes for ya northern folk? I would love to know the relativity between your areas and this area in Idaho. Landscapers love to use the straight species here (no clue why…its too big lol). It would give me an idea of relativity of how hardy my further generations of this species’ hybrids could possibly be. Maybe on of ya could test for me in the far future when I begin to get reblooming hybrids from my work with Rosa rubiginosa. I also would like to know the relativity for Rosa canina as well since my work with it is on the same timeline. I doubt it is as hardy as the former or Rosa laxa. I never trust references for hardiess.
When I lived in Duluth, Minnesota, R. rubiginosa survived pretty well but did suffer erratic cane damage. It was not quite in the same league as Suzanne–which was untouched by winter cold. I actually had quite a few unwanted R. rubiginosa as I believe Hortico was using it as a rootstock and it kept popping up all over–I ended up hating it as it was not a fun plant to try and remove. The canes on that plant could reach 9-10 feet tall by the end of summer and some winter damage actually knocked it back and helped keep it under control. Also, the hooked thorns were vicious to work around. But–the fragrance of the foliage was great! Applejack is just as hardy and a bit more mannerly–although it does break down with blackspot rather severely each year in my area. Through Applejack you get the influence of both R. laxa and R. eglanteria. BTW, Suzanne also suffers severe BS defoliation here each year. At one time I used it extensively but I only have one seedling I kept from my efforts. I am seriously considering removing it.
Applejack is not cane hardy in my patch of southern Ontario.
I didn’t mean to imply that Applejack is completely winter-hardy here. The canes die back somewhat erratically to about 24-36 inches most years (and occasionally worse than that), but it is comparable in hardiness to the hardiest Explorer roses–William Baffin dies back to a similar degree, and William Booth and John Davis are generally worse. There are some species roses, some species hybrids, and rugosas that are completely hardy here, but no modern appearing cultivar even comes close to being completely cane hardy. Some like the Explorer roses and Applejack retain some viable wood and they rebound well to form large roses each season. I was mainly comparing the hardiness of Applejack to that of R. rubiginosa, which also dies back with a very erratic type of cane damage. One cane might survive intact and the one next to it has 12 inches of live wood. Applejack has the same type of die-back but it is a much nicer rose and still has the marvelous fragrance associated with R. rubiginosa foliage. Most seedlings produced using Applejack (as the pollen parent) will usually survive here.
Lydia and Julie,
What roses or species roses are hardy in your area. Also, what roses or species roses take damage or barely survive? Of all of these, which ones repeat? This would great to understand the relativity of where the line is drawn in your area rather than relying on USDA zoning, which is crude at best.
Im surprised that Applejack gets blackspot there. It and its hybrids have been promising here in blackspot country, but we prolly have different strains.
The totally hardy roses I have tried that show some repeat are Suzanne, Altaica, R. arkansana, R. fedtschenkoana, and the rugosa roses. Non-repeating hardy roses I have (or had at my former home) include R. virginiana, R. carolina, R. palustris, R. woodsii, R. nutkana, R.acicularis, Alika, R. glauca, and many different R. spinosissima cultivars, although I have lost a Harison’s Yellow, a Hazeldean, and also Hugonis. R. foetida and Austrian Copper can survive the winter but fail quickly due to near constant lack of foliage from BS infections. Roses that suffer significant winter damage but are still able to bloom well include R. eglanteria (only the species, not any of the hybrids available), Geranium, R. setigera, and a thornless R. wichuriana (primarily because it stays beneath the snow). Roses that survived the winter but had few or no blooms due to yearly cane loss and were eventually removed after several years include R. macrophylla Doncasteri, R. multiflora, and a 4X R. stellata that David gave me to try. My R. beggariana is struggling to get established and is still small and weak after two years in the ground. I also lost a R. pendulina during the first winter, which surprised me as it was healthy and a good size going into winter. I’ve never been able to get a hold of R. laxa to try. Years ago I germinated several R. laxa seeds but they all failed the first winter outside. I’ve tried so many others over the years that I honestly don’t remember all the failures.
The backhoe removed a very large Applejack last weekend. It has been 75-90% defoliated from BS every year for the last 4 years. I think that David Zlesak said that it was doing the same thing in the Twin Cities area. Years ago I did a cross between William Booth and Applejack. I had 6 seedlings that were healthy in the ground for 6 years before they began to break down at the same time as Applejack, and just as severely. I now have only one of these seedlings that remains BS-free.
What a difference geography makes. R. pendulina is completely hardy here, also Henry Kelsey, John Cabot, but old wood has to be pruned out to keep them looking good. Also Louis Riel & Metis. Metis gets cane dieback at the end of summer. A seedling of R. paulii rosea never has any damage even in the worst winter. Seedlings of L83 & William Booth show little damage. Hybrids of pendulina & the William Booth seedling show no damage, but are susceptible to mildew, which neither parent gets. No winter damage on Prairie Dawn but it gets bedraggled & spotty as the summer progresses. A hybrid of pendulina & Prairie Dawn has been hardy over several winters living in a pot. Prairie Dawn prunes like a hybrid tea, so it’s always producing new stems & blooms. No winter damage on R. primula or Williams’ Double Yellow. Applejack & Carefree Beauty are healthy here, but if I get 8 inches of clean cane on either one, it’s been a good winter. Carefree Beauty is capable of producing seedlings with better cane hardiness even when the other parent is cane tender. Seedlings of Calocarpa are usually damage free on newer wood with older wood showing damage towards the end of summer. Mutabilis is dead to the ground but rebounds nicely even after the worst winter. Most winters show no damage on the gallicas, but in a harsh winter, the blooming canes are killed. Mme Isaac Peirere is cane hardy here, but in Canadian 5a its canes are dead to protection. Ottawa is 5a & a resident tells me that a bad winter can kill John Cabot. Sydonie and Mme Hardy show no damage most winters. Sydonie is the most productive rose in my garden, usually among the healthiest, but its as sterile as a rose gets. My sister had William Baffin in a similar zone & it never showed any damage. How odd that Applejack & Carefree Beauty lack cane hardiness here. I wonder if its the fluctuating winter temperatures.
I just remembered Chianti. In an average winter it will only retain new canes if they are laid on the ground & protected. This past winter was warm so it bloomed very nicely & produced many op hips. Unfortunately it hasn’t kept any of its leaves.