This is 1022 x 1113. 1113 is another seedling of unknown parentage…suspecting it includes Rainbow Knock Out and/or Prairie Joy. A bland single pink rebloomer that i used a lot because of it’s perfectly shrubby habit, like a dwarf spirea. This seedling is a once-bloomer that usually dies back more but is stunning this year after a mild winter with no dieback.
Here are some 1022 x op from an outdoor seedling bed that I let grow up en masse. Some are sweetly fragrant, some are completely thornless:
the above seedling is more magenta and is completely thornless. It seems likely it was pollinated by the nearby CAROCENTICOM which is (R. carolina x R. centifolia) x Commander Gillette.
I figured – particularly based on the profusion in those first flushes, but one can hope! (I suppose in your climate you would get limited flushes in a season regardless.) Nice that you got a few thornless ones in the lot though.
Are you working with R. setigera serena by any chance? Might be an interesting one to throw into your mix. I have dabbled with her, but I don’t have much to show for it (or for any of my other crosses for that matter!)
I do have her, trucking along in a neglected ‘back lot’…but in the past didn’t get good germination.
I am realizing somewhat late in the game that I should have been breeding more intentionally for thornlessness. It is a pretty valuable characteristic that might appeal to landscapers…a thornless and hardy Knock Out, for instance.
Absolutely! Thornless is the ONLY way to go, unless you need the prickles to help protect against grazing wild life. They won’t deter damned rabbits or squirrels but MAY deter larger herbivores (at least a little…hopefully). But, yes, if you want more municipalities to plant them, they need to be “un armed” so there aren’t any injuries to the maintenance people who are tasked with grooming and maintaining them. Not to mention how beneficial not being RIPPED by them is to us “old farts”. I never had bleeding issues until I lowered my cholesterol. Now, after a little while gardening, I resemble a slasher movie! And, I’m not on any blood thinners!
I’ve gotten consistently good germination from the commonly cultivated female clone of Serena Group (since it was originally a forma describing an entire wild population, I’m not keen on mere cultivar status for it…). Smooth caned offspring aren’t overwhelmingly likely if it is the only source of that trait, though. Crossed with relatively or entirely smooth-caned mates, your odds of smoother-caned seedlings improve quite a bit. Of course, with R. setigera, you always have the side benefit of likely RRD resistance in the offspring. In my experience, the key with germinating most Synstylae (including R. setigera) well seems to be drying the seeds thoroughly (ideally weeks to months), then soaking and moist stratifying; maybe even more than roses with larger, thicker achenes, they seem to benefit from the after ripening and achene hardening that occurs during an initial dry rest.
Stefan, wave you gotten any thornless f1 out of setigera serena? I haven’t worked much with mine as she took a half dozen year hiatus from blooming after I moved, but never got anything thornless, and ended up losing/culling the seedlings I did get.
This year she (at long last) bloomed again after a wet spring (note to self: try watering) and I have decent hip set. Mutabilis is always a willing daddy, and a pollen worth trying to “proof” reluctant seed setters imho, but more interesting to me are the hips I have from Moje Hammarberg. (Thinking perhaps a Geshwind-esque rambler in the F1?)
I have been losing practically everything to damping off the last few years and might be convinced to share, Joe, under the assumption you are having much better luck in your seedbeds. (David Z. if you are following, I tried to reach out to you via p.m. to ask if you would be interested. I know you were working with that species and towards cold-hardy plants.)
I was on blood thinners a couple years ago, and found a new appreciation for thornlessness. First time back in the rose garden and didn’t even realize I was pricked until looking down at my khaki shorts. I looked like I had lost a long, gruesome battle with a chipmunk.
(Beforehand i always reasoned that having to endure a few thorns seemed to make the rose smell sweeter, or some similar poetic nonsense.)
Wow, the chipmunks down there must be a pretty different breed from the ones I grew up with in the North
I certainly have gotten smooth-caned seedlings from Serena Group, but generally only when it was crossed with other at least relatively smooth-caned roses. I will also say that it can at least reduce prickles in some offspring from crosses with some fairly well-armed roses. A cross with ‘Darlow’s Enigma’ produced a seedling for me that is thorny on the lower canes but is smooth-caned or nearly so on most of its upper growth. Some of its siblings appeared to be even smoother-stemmed, but they didn’t have enough juvenile disease resistance to find out how they would mature. I probably wouldn’t expect seedlings from a cross with any normal rugosa to be smooth, but maybe a prickle reduction of some sort is possible–I haven’t tried anything in that direction.
I’ve found that it also pays to cross it with roses that have good foliage health, and if you don’t like grabby rachis prickles, that’s another trait that probably needs to be softened by the influence of the other parent.
Stefan, you means that you get thornless individuals from F1 seedlings of Serena, or after generations of line-breeding or inbreeding, and what’s the ratio of thornless ones in the seedling population?
What’s more, have you tried to cross two thornless cultivars with absolutely different background? If tried, would it result to thornless offsprings?
I haven’t counted to try to determine if there are any meaningful ratios, but doing so would be complicated by the unusual behavior of its particular kind of genetic thornlessness, and by the difficulty in getting all seedlings from a cross to maturity (which is necessary to determine whether they actually have a reduction in prickles and if so, by how much they are really being reduced). I would probably characterize the situation as one of incomplete genetic dominance, and probably not the same as the genetic thornlessness found in other roses.
Crossing R. setigera Serena Group with another completely smooth-caned rose is very likely to result in a number of smooth-caned offspring, although even then, not all of the offspring may be entirely free of prickles. I have not made such a cross deliberately, but I have seen this with spontaneous crosses between it and the thornless variant of Rosa lucieae (a.k.a. R. wichurana) known as ‘Basye’s Thornless’, which tends to overlap it in bloom. One such seedling is free of stem prickles, while another is mostly free of them, but some small ones still appear occasionally in odd patterns on certain stems. A deliberate crossing between those two might be useful to shed further light on the situation, but you would need a tremendous amount of space to grow out the offspring!
I know that we’ve discussed this in other threads on the subject, but there seem to be relatively few available sources of reliably heritable genetic stem thornlessness in roses. Hardly any have been studied scientifically to characterize the genes or alleles that are involved, but one that has been studied is the ‘Basye’s Thornless’ that I mentioned: Rose without prickle: genomic insights linked to moisture adaptation - PMC
Of course, ‘Basye’s Thornless’ still has plentiful rachis prickles, and it gleefully passes them along to its offspring.
The deer in my southern Indiana locale won’t eat prickly canes, so they strip off all the leaves. Some mornings (especially if I forget to routinely spray “Liquid Fence”) I’ll awaken to a garden of long, leafless canes.
They LOVE my Aimee Vibert, and do munch those largely thornless canes, but Leave Zephirine D’s thornless canes alone. Go figure.
However, they don’t seem to like the texture of rugosas, and those are always left alone.
Thanks.
I have read that article and surprised that a fair amount of F1 seedlings of BT x OB are thornless. If thornless is controlled by a single gene, that seems impossible. Anyway, that seems thornless is not very difficult to inherit, at least in BT.
In the book Encyclopedia Of Rose Science, absence of rachis prickles is rated as dominant. However, it’s weird that roses with thornless rachis seems rarer than ones with thornless stems.
I think that the allele present in ‘Basye’s Thornless’ must be dominant, so if the seedling receives even a single copy, it should be smooth-caned. The cultivar must also be heterozygous for that allele, or else all seedlings raised from it would have no stem prickles!
The scarcity of cultivars having smooth rachises could very well be due to a lack of interest in selecting for that trait (why bother, when smooth stems are so uncommon in the first place?). In my opinion, just like we see with stem thornlessness, it isn’t likely to be due to a single allele that was inherited in all of those roses from a single shared origin. So, maybe one allele was found to be dominant, but that doesn’t necessarily mean they all are.
It would be very useful to have lists of roses with smooth stems, smooth rachises, or both (preferably ones that are actually available today, and ideally ones that have other garden-worthy characteristics) that will also reliably pass those traits to their seedlings.
Thanks for recommendation. I agree with most varieties in the list, with few exceptions:
Veilchenblau. Sparse prickles present on stems, not absolutely thornless. Maybe my plants are ‘Violette’ but that seems impossible anyway.
Lady Hillingdon. Very large, sharp prickles on large shoots, smaller ones on branchlets, not to mention rachis.
I would add these varieties to the list (except for rootstocks):
Kew Gardens (Austin). Nearly completely thornless on stems and rachis. Seems not heat tolerate, new growth tend to be “mossy” in heat weather.
Susan Louise (Hybrid gigantea). Nearly completely thornless on stems, sometimes prickles present on rachis, but quite weak. Large high-centered flowers, good rebloom but somewhat prone to blackspot.
Napoléon (china). Completely thornless on stems and rachins. This variety is very fragrant but very prone to blackspot.
Koster roses. Some are thornless but others possess sparse prickles on stems. Very blackspot resistant but prone to mildew.
Rosa chinensis, Cl. A semi-double crimson form with smooth canes but thorny rachins. Once blooming. Likely a Chinese landrace.
Several hybrid multifloras, usually categorized as “R. multiflora Thunb. var. carnea”. Usually thornless on stems but not on rachis. Many varieties, usually with relatively large (compared to wild R. multiflora), semi-double to double (even button-eyed), nearly white to pink or lavender flowers in small to large clusters, sometimes fragrant, once-blooming. Most are disease free but some can get blackspot (still better than most modern roses). They are likely Chinese landraces.
Duchesse De Montebello (hybrid China). Almost thornless on upper part of stems. Hairy prickles present on lower part but seems too weak to make trouble.
I found that most thornless varieties are once-blooming large climbers or ramblers, maybe they are very unlikely to be preserved if they possess prickles.
You could also consider the diploid multiflora/chinensis derivatives sold as Angel Wings/R. Chinensis minima/Party Mix and a few other trade names. They are propagated via seed and sold in cheap seed packets.
In my experience, a good percentage of these grows to have completely thornless stems. Of course, since they are reproduced sexually it may vary depending on the source.
I bought a 30 seed packet for something like 2€ on ebay, so it may be worth trying.
I have a good number of hips from modern tetraploid × angel wings, hopefully I’ll have seedlings next year
That sounds interesting. Perhaps it is possible to select individuals with desired traits (or out crossing with suitable varieties) from these seedlings and then do inbreeding, thus may result to an improved stable, uniform seed strain. Now many perennials and bulbs, like cannas, dahlias, geraniums (Pelargonium), windflowers (Anemone coronaria), buttercups (Ranunculus asiaticus) and even lilies (Lilium longiflorum and L. formosanum), which are commonly vegetatively propagated, now have commercial seed stains (especially F1 seeds) introduced by large companies like Sakata, Takii and PanAmerica. I haven’t heard any roses like this, so that may be an interesting (or crazy) thought.
