Rosa eglanteria - A species for developing cold hardy bicolour Climbers?

Although I’m in a Zone 3 climate, last winter’s temperatures were probably the mildest on record. Essentially, it was a Zone 4 winter in north central Alberta. A Rosa eglanteria used as rootstock growing a couple blocks away survived the winter well and grew vigorously during the summer. It reached 3 metres tall and flowered profusely. I thought I would take advantage of it for breeding purposes. Most of my crosses with it were with ‘Hazeldean’. My idea is to deveop a breeding line that could be used to develop cold hardy (Zone 3), bicolour Pillar or Climber roses. I note that ‘Lord Penzance’ has a similar parentage (‘Harison’s Yellow’ the staminate parent). ‘Lord Penzance’ is not a strong bicolour of pink and yellow, but there is no doubt this colour characteristic is derived from Rosa eglanteria.

If I can get a good Rosa eglanteria x ‘Hazeldean’ bicolour selection, then I have to consider what the next step is to take. It’s likely I would cross it with Rosa laxa x Rosa spinosissima altaica or Rosa laxa x ‘Hazeldean’/‘Prairie Peace’ hybrids that I am currently developing. I’m also likely to try it with some relatively cold hardy, good quality, fertile cultivars like ‘Applejack’ and ‘Prairie Princess’.

Next year I plan to cross Rosa eglanteria with the J5 Rosa spinosissima bicolour. I may lose some cold hardiness but this should be offset with increased vigour and tall growth in the progeny. J5 is fairly tall though; it can reach 2 metres.

It seems to me that breeders in the past using tall, vigorous species like Rosa eglanteria and Rosa laxa in their breeding programs do not take advantage of the natural characteristics of these species. While they want some of their excellent characteristics (usually cold hardiness), they want to “knock them down” to produce relatively short shrub roses. It can and has been done (eg. Griffith Buck with Rosa laxa), but this usually takes considerable time and effort to accomplish. In the case of Rosa eglanteria, it’s time to use this species for its great character- istics of vigorous, tall growth. Also, of course, its ability to produce bicolour flowers along with fragrant foliage in its hybrid progeny.

Who else is working with Rosa eglanteria? Although it has been used in the past (but a long time ago) by professional breeders, this species seems to have been neglected by amateur breeders.

R. eglanteria is one of those that does not split its chromosomes evenly. Since it has either 35 or 42 chromosomes, I would expect that pollen of another rose would not change its characteristics very much.

Thus, it would probably be better to use it as the pollen parent (7 chromosomes).

I have looked at open pollinated seedlings of Hebes Lip. They are strong healthy plants with good full flowers but only once blooming.

If you look at Help Me Find and do a listing by generation, you will find many familar roses have some eglanteria blood.

Possibly the pollen may benefit from some extra calcium.

Title: Effect of calcium and sucrose concentration on pollen germination in vitro of six Rosa species.

Authors: Koncalova, Marie N.; Jicinska, Dagmar; Sykorova, Olga.

Authors affiliation: Bot. Inst., Czech. Acad. Sci., Pruhonice, Czech.

Published in: Biologia Plantarum (1976), 18(1), pages 26-30.

Abstract: “The presence of Ca2+ resulted in increased pollen germination, longer pollen tubes, and in a decrease of the requirement of sucrose concn. in cultivation media. Pollen germination in the medium with Ca2+ reached the values of pollen viability estd. by the tetrazolium test in all cases except with roses with balanced heterogamy, of the Caninae. The stimulating effect of Ca2+ was generally most pronounced in the pollen from hybrid roses such as R. jundzillii, R. canina, and esp. in the case of the calciphilous species R. eglanteria.”

I tried tot hink of alternate species that were more breeder friendly but the choices kinda suck for that hardiness range. Where is the climbing genetics coming from, though? Or is this project like that of Westerland where it is a large enough shrub that it appears to climb?

I was looking at this species this summer because it seemed like this is where flavenols (sp?) came into the picture for OGRs in order to express some mauve tones more vividly. It was just a guess anyways. I imagine that, similarly, this would aid in expressing more vivid blends, too. Ive noticed that Rosa californica (the lighter native in my area, not the dark kinds from california) has a sheen similar to Rosa eglanteria in it’s petals. Im guessing it has flavenols, too.

What about crossing one of the yellow hybrids with R. kordesii? Something like: Prairie Sunset x (Rosa kordesii x Hazeldean)

I love R. eglanteria and have been doing breeding with it from when I started in the 1980s. If I knew about Caninae meiosis and the challenges there I might not have began, but am glad I did. Using it as a male, although theoretically good because it should contribute only 7 chromosomes, hasn’t worked well for me. The few crosses and seedlings I got were weak and died. Perhaps I used the wrong females. I have been using it successfully primarily as a female. I have some 5x and 6x offspring from it. Some of the 6x offspring have pollen the diameter expected for 2x pollen, so there may be modified meiosis like for R. alba. There is also a 6x hybrid (5x eglan x a tetraploid modern rose hybrid) that has pollen the diameter expected for 3x pollen so meiosis may be more normal. I should keep trying these 6x hybrids as males. I have some R. eg hybrids with rugosas, other caninae section species, ‘Haidee’, ‘Applejack’ and others. The healthiest seedling surprisingly is from R. eg x R. pomifera. It even roots well from cuttings, has a lot of vigor, and flowers about 2x the diameter of normal R. eg! It’s 5x as expected. My original R. eglanterias are 5x. My hope in general for R. eg is to use it and its hybrids enough generations as a female (seems to be the only way so far I’ve gotten viable hybrids) with repeat flowering males to eventually get repeat flowering offspring that still retain strongly fragrant foliage. It’ll probably be a life long project that I’ll hopefully compete or hopefully someone else will continue it after I die if I don’t get there.



William Baffin is reportedly hardy to zone 3 and is relatively disease free. There is one at a rose garden 30 miles from my house(northern zone 4) that is over 10 feet tall. If you could create a large climber with bicolor flowers and apple sented foliage from R. eglanteria that would be awsome. I was thinking of using Applejack with William Baffin because Applejack reportedly has apple scented foliage and better disease resistance than Willam Baffin. Applejack has R.eglanteria in it thru Magnifica from both it’s parents.

On a related note, I was thinking about R. glauca which is 4x(3+1). I was speculating that if you crossed a 6x R. acicularis with it first, all three R. glauca chromosomes might pair up with the three R.acicularis chromosomes, which would hopefully normalize the meiosis. Another possibllity is that two of the R.acicularis chromosomes would pair up, one of the R.acicularis would pair up with one of R.gluaca chromosomes and the other two R.glauca wouldn’t pair up at all. Or lastly there would be no pairing of the R.acicularis with the R.eglanteria chromosomes at all. The last two cases would likely have 2x pollen.

Based on what David has seen with the R. eglanteria hybrids there seems to be no or limited pairing of R.eglanteria chromosomes with the pollen parent. But because of the different number of chromosomes involved with R.gluaca and R.acicularis the results might be different.


The article that I found the most interesting on the subject of Caninae inheritance is the one in Heredity, volumn 92, pages 139-150, (2004) by Nybom, Esselink, Werlemark, and Vosman.

If you type in the above reference into Google Scholar, you will find the papers that have since cited the above paper.

It appears to me to be saying that the 7 chromosomes donated through the pollen do not contain very much (if any) species-specific information (they contain mainly information that is common to all roses). If this is a correct interpretation, then, say, 7 generations of crosses with, say, a rugosa as pollen parent, would not normally give a rose that looked mainly like a rugosa.


Flora McIvor is given in Modern Roses 11 as “(R. eglanteria X HP or B)”. (B means Bourbon or climbing Bourbon)


In the past I have distributed open pollinated seeds of it. Dave Zlesak posted the following:

I received some of the seed that Dave offered and at least one second year seedling is in the garden (but has not yet flowered).


Meiosis in R. eglanteria hybrids and other Caninae section species I suspect is very complex and depends on a lot of things. The French research group that extracted haploids out of cut hybrid teas also extracted plants out of a R. caninae eggs (4x plants instead of 5x). This 4x plant did was missing a set of chromosomes that normally would be involved in pairing. These 4x plants did not have stainable pollen and suggests that another “genome” did not replace the missing one to be involved in pairing. I have a 3x R. pomifera from the same sort of derrivation (twin embryos- one was 4x and from normal fertilization and the other one, 3x, probably is a synergid that developed into an embryo and has the same chromosome contribution as the unfertilized egg). This 3x R. pomifera has as high of fertility as its 4x sibling and 4x mother. It has highly stainable pollen and about as many seeds per hip as its 4x sibling. From either selfs or crosses with its 4x sibling (all in bloom at the time) it produced seedlings that when I counted chromosomes of a sample were also all 3x. So, at least in this R. pomifera there is some substitution and plasticity for pairing. Also, in the 6x R. eglanteria / Haidee hybrid and hybrid with another 4x breeding line, the diameter of pollen expected for 2x pollen also suggests that perhaps some other R. eglanteria “genome” is pairing with the one left that normally is involved in pairing.

I think that the idea of “genomes” is useful for understanding meiosis and making things simpler. It may be too simplistic, however. In wheat there is a gene on chromosome 5 of one of the 3 “genomes” that controls uniform pairing. When it is knocked out all “genomes” can pair. The chaos often leads to broken sets of chromosomes (aneuploids) and low fertility. Perhaps there is just a gene or few genes controlling Caninae pairing which stabilizes meiosis and when disrupted by interspecific hybridization or other means allows for more freedom in homeologous chromosomes to pair. I’m excited to have some Caninae section species hybrids that seem to have variable meiosis and think that they may become good bridges to bring in the traits I would like to into modern repeat blooming roses. For instance, I think this 3x R. pomifera crossed as a female to modern repeat blooming tetraploids can hopefully produce some tetraploid offspring that is only half R. pomifera and help save time before getting repeat bloomers and also have the hybrid be in R. pomifera cytoplasm if that influences the nice foliage fragrance (maybe it doesn’t??). I look forward to learning what others obtain with the 3x seedlings of this R. pomifera plant in the future. There seems to have been segregation for leaf size and vigor among the seedlings, which hasn’t really happened for me with standard 4x R. pomifera which was probably selfed. Anyways, using R. pomifera as a female in intersectional crosses is the only way I’ve been successful, so using it as a male hasn’t really been an option yet for me.



Hi David, as you know I now have this fertile triploid pomifera thanks to your generosity. I will be trying it come Spring as you suggest provided we get enough chill to provide it’s requirements. I look forward to working with it. Would you only try tetraploids with pomifera as seed parent? Would my fertile triploids be worth a go? Thanks, Robert

Thanks to all for your comments. Hopefully, they will stimulate more interest to work with Rosa eglanteria in breeding programs. Paul, I’ve taken note of your suggestion to cross Rosa elganteria with Rosa acicularis. I will do so next spring using the ‘Kinistino’ cultivar developed by Bob Erskine. The flowers are almost red and the leaflets are large. I will also use Rosa moyesii ‘Geranium’ (likely another hexaploid), which has surprisingly good (Zone 3) cold hardiness. My Rosa woodsii x Rosa moyesii ‘Geranium’ produces somewhat bicolour progeny, so perhaps it will also do so (be more effective?) with Rosa eglanteria.

Hi Robert, Crossing your ‘River Banks’ and ‘Lila Banks’ with the 3x pomifera sounds like a great idea. It looked like many of the pollen grains of these would be the diameter expected for 2x pollen. I have been thinking of just mainly 4x males (triploids are a great idea too) just try to get 4x offspring because they may have more fertility, but triploids seem full of surprises regarding their fertility as well.


Rosa moyesii cultivars seem to produce climbers. Well, the lineage is kind of obscure but it seems plausible from the information on HMF.

One of the things I find confusing is trying to decide which section of Caninae to go with?

I find I am more of a lumper than a splitter. I wonder if there is any advantage in using one member of the group over another?

I will probably choose to use David’s pomifera among other things but it’s definitely only one of several options.

David, Thank you for the information on your 3x R.pomifera. It expands on what I suspected might happen when polyploid pollen is used on a member of the Caninae section. I agree that there must be a gene or genes on the univants that is preventing them from pairing. Perhaps the bivant from the non-Caninae will be able to overcome this and pair up with them.

The 3x R.pomifera is quite a remarkable plant. I think a second embryo from a seed would be very easy to miss. A seedling from an unferilized egg that is highly fertile must be rare. It looks very promising for integating R.pomifera characteristics into a repeat blooming tetraploid. You will have to keep us up to date on this.

How often do think these synergid or unfertilized eggs happen? They might be the best way to get Caninae chacteristics into modern repeat roses.

I was origonally thinking that first crossing the Caninae with a hexaploid might help stablize the meiosis. Then crossing the offspring with a repeat blooming tetraploid.

I now think, like you, that it might be faster to cross with a repeat blooming tetraploid right off the bat. Hopefully there will be chromosome pairing of two different genomes. You could then either cross two of the resulting siblings or back to a repeat blooming tetraploid. Hopefully this second generation would have repeat bloom and the Caninae charctaristics you wanted to incorporate.

Paul, I would have never guessed that R.moyesii’Geranimum’ would have been hardy to zone 3. That and Kinistino look like they will be excellent choices to work with. You will have to keep us up to date on your progress.

The R.acicularis that I have are seedlings and probably won’t bloom for another two years, so I won’t be able to experiment with them for a while.


Hi Paul, Twin embryos with one derrived from a synergid doesn’t happen too often. I have only had a few confirmed cases. ‘Dorcas’ has produced two 2x/4x twins. I have also gotten a haploid out of Rise N Shine that is yellow! Unfortunately it isn’t fertile- no anthers and doesn’t set hips. I think the key for generating haploids is to try to get a lot of them and then hopefully have some with fertility. Unfortunately, the haploids out of ‘Dorcas’ died. They grew very well at first and bloomed well. They just eventually fell apart and died. I think that the reason I’ve been able to observe twins is just because I germinate seedlings in baggies and transplant them at an early stage and can see and baby twins.

I’m excited and thankful for the 3x pomifera. It actually seems a bit more vigorous than its 4x twin. Cytogenetics and chromosome pairing and contributions sure are interesting.



Hi David, I read Ann P. Wylie’s article “Why the Caninae roses are Different” again. It discribes the very same observations that you are seeing. She even talks about a plant derived from an unfertilized egg. It’s encouraging to see that when non-Caninae chromosomes are introduced some of the Caninae univalents also pair up. It’s also interesting that lower tempatures allow more univalents to pair up. So if one pollenates in the morning or on a colder day, they might get better results.

It’s too bad your other haploids haven’t worked out for you. I also germinate small lots in baggies. I’ll have to keep an eye out for them.

Thanks, Paul