Ploidy questions - Taking Steps Towards Building Genepool

I’ve been playing with OP hips now for a good maybe 5 years or so? At 20 I still have my first seedling, a ‘Queen Elizabeth’ seedling from when I was I think 17 out planted in our yard. Tiny runty thing, but I kept her anyway. This year actually is the first year in a LONG time I’ve gotten seedlings to not dampen off on me, and have one looking to bud soon out of random 7 or so current seedlings.

However this summer I’m looking to try some actual direct crosses for the first time, with actual emasculation and such, I did a little bit this year, but it was rather informal, just lot of finger smudging…but I’m still a bit confused by the whole ploidy thing. I’m good with aesthetics, not numbers!

Roses I have available or will be available for eventual use:


‘Plaisanterie’ (This one is outstanding, I want to cross this with everything else! I feel it has a lot of potential…)

'Roseraie de l’Ha

Hi Max!

Here are the ploidies of some of them in question.


Rosa maximowicziana (I think it is the one I sent you)

‘Pax Apollo’

‘Pacific Pearls’




‘The Gift’


‘Lynnie’ I was so surprised to find this one to be triploid, especially with all the hips it makes.

In general, I think the key is to find your female parents that are fertile and produce seed that germinates for you and try different roses as males that you would like to try. Some combinations may not produce very many or any viable seedlings, but the fun of it is to develop interesting and valuable seedlings you enjoy and not always raising as many seedlings as possible. The crosses that work better and still produce the types of roses one is intersted in seem to be what we gravitate towards.

THe polyanthas and R. max. cross really easily with each other and in one additional generation to a repeat bloomer you’ll get repeat bloom back. I’m at that point now with my R. max hybrids. They inherited really good winter hardiness from the R. max. clone.

Take Care Max!!



One comment:

‘Marianne’ is almost certainly a tetraploid, but it has never formed seeds in the 9 years I have had it, even when pollinated manually. I have attempted to find pollen on several occasions but at most found one or two anthers, so I didn’t bother to use them. I insist on collecting at least ten fully formed anthers before I will dry them and try to extract their pollen. In a different climate it might be more willing to produce pollen, so its best to find out for yourself. I have often wished to be able to move forward with that rose, as it has many sterling qualities and I can imagine it producing remontant offspring of great beauty and charm. Perhaps I will try looking for pollen again this year.


I am like you in that I am pretty much just starting my breeding program. So I do not know if what I am saying will be helpful or not. So take what I say with a grain of salt. I believe that you have to first consider where you want to go and then make crosses that reflect that.

For me I like minis and minifloras. I think smaller roses are going to be more important in the future as gardens get smaller. But I find the greatest need in this class and actually most rose classes is disease resistance. Roses have gotten a bad name among gardeners because of being bred too much for perfect flowers and not much for the plant. Secondly I want to breed for winter hardiness because of my climate. For my climate winter hardiness depends on the variety not so much withstanding great cold but staying dormant through many false springs and also on it being able to withstand a winter with hardly any water. These two factors cause more plant lost than anything else for me.

I also want to expand the gene pool of roses. With an expained gene pool I beilve new important traits can be found and horizontal resistance will increase.

I also like mossing, foliage color, and scented foliage would be great. But these are side pursuits so if a plant could not contribute to my other goals I did not consider it. I also like unusual colors and stripes but again it must contribute more than that to be considered for me.

Since most modern miniatures are tetraploid or breed like tetraploids I want to stay mostly within this framework but that is not a hard rule. Ralph Moore and others have sown that in roses ploidy rules can be bent.

I considered all my crosses this past year as a possible stepping stone. The female parent to most of my crosses is a miniature these mostly lack the winter hardiness I wanted and the disease resistance I want but they were important to me because the provide the continuous bloom, the expanded color lines and most importantly they were the better female parents.

For male parents I tried to use plants that were disease resistant and hardy like William Baffin, L83, Complicata, Cuthbert Grant.

I expect to get plants that probably want to bloom twice during a season, have only a little more winter hardiness and lack greatly in the disease resistance I want. But these plants are the stepping stones I want. By selecting from the best I can make baby steps into the future. I plain on crossing these back to parents like William Baffin and also to first generation seedlings. After two or three years I should know what seedlings work best in this generation. Mean while I am plaining to make more first generation crosses this year.

So I would first consider where you want to go and then plain crosses accordingly. Try to find your good female parents and use them that way. Since most of your plants seem to be diploid I would stick mostly to diploid x diploid crosses. but don’t choose not to make a cross you have a gut feeling about because of ploidy. Others have had success breaking the rules.

I like to think of ploidy as degree of difficulty. I had an awesome analogy about armor points stacking with evasion skill for the near-sterile types but then I realized Ive played too many video games lately =/

In the past 15 years I have found that triploidy is rarely as much of a fertility barrier as some of the literature would have me believe.

I have a number of confirmed diploid and tetraploid plants that have little or no fertility. I have several confirmed triploids that I used frequently (‘Golden Angel’ and ‘Out of Yesteryear’ to name but two) which are highly fertile as both female and male parents. To new hybridizers first learning about ploidy I would say: put your time and energy into finding out which plants actually work as parents and try not to make assumptions about a plant’s potential based solely on its ploidy.


You are young-if you were starting out doing this at 60+, then I’d agree that you should perhaps figure out some of the nuances of ploidy,get your goals lined up,etc., but you aren’t 60+. Give yourself another year or two to get down the basics of making crosses, determining what is important to YOU in regards to how you want to see progress. Keep reading, get a few books,i.e., Botany for Dummies, or Roses for Dummies, and of course look it up on RHA using the SEARCH option. And then there is HelpMeFind, and the several rose forums. And plant more than rose seeds–nothing teaches you how to grow things well faster than growing many things. And that goes for making cuttings, grafting,(my first graft was on my mother’s pear tree)and observing. Being able to discern when a tomato is dry or needs fertilizer is not to much different than from a rose seedling. Many of the cultivation questions on this forum do relate to a lack of skill with growing plants from seed in general, and especially with lack of history with roses. There is so much to know about the past and present in roses that you should set up a few alternative experiences (roses under lights, roses in your window, under glass) and try as many simultaneously as you feel that you can handle. And then scarf a few OP hips off neighbors and public roses, divide each variety in two batches, and try differing planting mediums, stratifying techniques, watering techniques, on and on. And don’t be to concerned with what can or cannot be done, if you feel based on your hunches that it might be done. And one day we may hear that you have produced something newer, hardier, better, more resistant ------You fill in the blank. Jackie

Thanks for the input everyone! I’m overthinking things…I should just try things together then and go from there.

it’s a wonderful hobby, I get a kick out of collecting hips, and almost was arrested because I was picking hips off of a bush in front of a medical center…oops. But yeah, I’d rather produce shrubs that I’m proud of or interesting to me more than anything.I think in the past two, three years I’ve tried to be far too “big” scale, entire jiffy flats of seeds that would produce stringy tall seedlings that after watering ALL of them, maybe was just too wet an environment. This year I went back to basics and only did a few at a time. It worked!

And yes David, the maximo rose is of the bunch you’ve sent me! It’s doing great and handles a tiny bit of shade. I have it next to a rhododenron that suffered a ton of dieback, so idea is that it will “eat” it until it builds back it’s size.

I missed it’s flowering because I was in Japan for study abroad but I so far love the foliage! It’s grey and very pretty! I like it a whole lot better than the damn Multiflora in the woods. A lot of the small cuttings you’ve sent me are actually doing rather well if not spectacular. I really want to thank you for sending them! If you ever want some more perennial seeds just email at my new school email on the contact thing.

So yeah I was overthinking. I tend to do this with EVERYTHING so I’m glad to hear my thinking is not too off…

And Paul, that’s a shame with ‘Marianne’! I’d love to breed more apricot gallicas or increase the gallica color palette a bit, it’s so unique!

Actually the look for the gallicas I’d want to try to produce would be halfway in between ‘Marriane’ and the spins ‘Musician’ and ‘Prairie Peace’ with a more ‘Tuscany Superb’ habit, since they’re tetraploid they might not be a bad thing to try purchasing when I have the money to dabble in!

Adam, I think you sound like a much better organized beginner than myself! Sound so prepared! Have you ever considered using the mini gallica ‘Burgundian Rose’ in your breeding? It could amp up hardiness and shrubbiness for sure. You would loose remoanantcy though for a while…

Anyway thanks again guy’s, I’ll keep everyone updated on my seedlings!

Max I have considered Burgundian Rose. It was one of the plants that did not make it because room issues.

And I am not that organized. I just try to restrict myself to the main goal. With that said I still did some crosses last year just to see what happens. For example I did some crosses using Angel Face which really do not fit in the main program. I also made a lot of crosses with R. glauca which may in the end work it way into my program but most of those crosses was just to see what happens.

You could make small crosses at random with your plants. By doing this you can determine what is willing to accept the widest amount of pollen. You can also determine your better seed parents. And by looking at the seedlings you can determine what crosses show promise and do those crosses in bulk. In a lot of ways the seedlings you select will show you what you favor and you could use this to determine your goals.

Marianne is a wonderful rose so if you ever do find pollen I would use it.

David, thank you for determining Lynnie’s ploidy! Triploid? Wow! She’s as fertile as a Chinese rabbit on fertility drugs!

She’s as fertile as a Chinese rabbit on fertility drugs!

Has anyone looked at Lynnie’s pollen diameter?

David, have you ever tried doing chromosome counts on the cells in the ovary of a rose?

Hi Don,

No, I haven’t looked at chromosome counts on the female side. It would be very challenging to isolate the tissue and appropriate cells at the right stage of division to see the chromosomes clearly. Typically, people estimate the variation in female ploidy by trying to looking at the ratios of ploidy among offspring and using a male that typically produces gametes of a particular ploid. I haven’t looked at the pollen of Lynnie. I was super surprised when it was triploid and counted it a couple times to just make sure.

It has been really interesting to find triploid roses from crosses of two tetraploids from time to time. Pairing of chromosomes and how they segregate and move and all can be quite variable, especially I think at times in our very complex hybrids. I suspect sometimes the individuals with more unique plant habits, etc. stand out and triploids help to do that with their ability at times to be a good balance between growth rate, size of plant parts, etc. I was surprised when I first counted Knock Out as triploid and John Davis and JP Connell too. Then there are roses like Lillian Gibson and Topaz Jewel that with their pedigree and low fertility one would suspect they are triploid, but they are diploid and are just from such diverse background that likely limits pairing and fertility.



I can’t say I am completely surprised about ‘Lynnie’ since it involves ‘Golden Angel’ (3X) as a grandparent, and ‘Basye’s Amphidiploid’, an induced tetraploid. It is entirely possible that all the mixed ploidies in 'Lynnie’s very recent history have generated a line in which tetraploidy is not quite completely ironed out yet.

David, have you looked at 'Torch of Liberty’s gene count? It could also have been a triploid, coming from ‘Orangeade’ (4X) X ‘Golden Angel’ (3X). I can supply root tips of ‘Torch of Liberty’ if you want to check it. I have two plants in pots that I keep in the breeding house.


Hi Paul!

I would be glad to test ‘Torch of Liberty’. I remember it being one of the first minis I bought years ago. I don’t have it anymore. I’ll be glad to look at root tips of whatever you would like to send me Paul.


Paul, you spoke my thoughts! I sat here this morning thinking about this and it hit me that Torch of Liberty either is triploid or, like several other Moore roses, generates them. It’s been interesting following the ploidy threads and remembering all of the “rose legend” I’ve read of the infertility associated with the early Tea crosses. It seems not so much a ploidy issue as compatability in other aspects. Ralph really had hit on a “bridge” early on without even considering chromosome counts. You know he disregarded it early on without even being able to know what they were. His experience taught him it wasn’t important. Now, we need to supply David with material from Golden Angel X R. Ca. nana to see whether it’s bi or triploid. It will be hysterical when it proves to be tetraploid! Has the ploidy of 1-72-1 been determined? As easily as it accepts nearly everything thrown at it, that would be interesting. A whole line of “pan sexual” minis which mate with nearly everything. Talk about being able to pollinate it with dirt!

David, Kim,

I have gathered new growth root tips from my Torch of Liberty and will forward these to David asap. I can send David a sucker of the other one Kim mentioned if David wants to take a look at it as well.

“pan sexual” minis which mate with nearly everything"

It’s not just minis.

Fertility amongst some mixed ploidy standard sized roses is also remarkably common.

Our lack of awareness of what’s occurring at a genetic level is why these marriages have seemed unlikely to succeed in the past . In the end this just proves roses are remarkably fertile.

I think it’s important to keep in mind that full compliment of genetic material isn’t being passed along in these types of crosses. Much is lost on one side or the other.

I just finished counting ‘Torch of Liberty’ and it is triploid. What a surprise!


Surprise? Particularly when you consider how blinking fertile Torch of Liberty is! Another you can pollinate with dirt!

Still more evidence that the whole “triploids are generally sterile” notion is often untrue. Thank you David, for providing that information!