My “philosophy” or “way of thinking” about peony breeding is guided by a number of principles and factors.
I think I have seen fairly strong evidence that peonies generally do better with outcrossing, i.e. the crossing of two different parents. This is true of many plants but not necessarily all. With two different chromosomes in heterozygosity, there is a much better chance of a “good” allele covering for a “poor” or mutant allele and hence the organism to retain health. Of course, inbreeding, i.e. creating homozygosity, can exaggerate a characteristic whether good or bad. However, in peonies, wherever I have noted self pollen on stigmata (sometimes flowers shed their pollen before opening) before going on to pollinate with a desired, different pollen, I have often noted a reduced yield of seed at harvest compared to the same cross where there was no self pollen. Similarly, some varieties like Lemon Chiffon, seem to readily set seed without artificial help. However, on a number of occasions, the hand-pollinated Lemon Chiffon, seemed to grow normal seedlings, whereas the unaided Lemon Chiffon would generally grow a batch of very stunted “poor do-er” seedlings. My interpretation of this was that the unaided Lemon Chiffon was self-pollinating!
Because heterozygosity is generally healthier, I like to try and get as wide a diversity of seedlings as possible as I head toward a particular goal, i.e. I am trying to bring a population of seedlings along from widely varied sources. This will help to maintain fertility and health from generation to generation. I try not to get too fixated on a particular “magic” cross, which is like putting all your money on one particular horse race! I have done this in my efforts to get an early white double. It could have been a winner as there were desired characteristics in both parents, but in this case, just a disappointing number of mediocre seedlings!
Another important consideration is that time is short (!), and that I will only achieve a few generations in my time. For a number of reasons, I find deciding on the suitability of a new variety a slow process. Firstly, I find peony flowers tend to alter over the first few years of flowering. One incident that I remember vividly, was to rogue all the plants of a particular cross that produced a single-type flower in their first year, in a bid to be “efficient”. However, despite lifting a lot of rejects, I failed to remove them all, due no doubt to some other call on my time, or perhaps laziness. Imagine my surprise that all, everyone, of the plants noted as single in their first flowering, but unintentionally left to flower again, turned into doubles in the following year.
Secondly, seasons vary from year to year, giving different results. One yellow double seedling I had, had a particularly good year. The colour was strong, clear yellow, the double flower shape was very refined and symmetrical, and the bush was neat and strong. I felt strongly that this was the plant that all my hybridizing efforts would be remembered by. However, in the last three years since then, it has never looked particularly good.
So, because time is short, I tend to co-opt new seedlings into the breeding programme, even before I have made final decisions about their worth as a possible named variety.
When it comes to the actual crosses I make year by year, some are planned because of previous years’ results, but quite a lot is decided on the day as and when I see the flowers opening. I have the overall goals, e.g. early white, late true red, in my mind, but I also have a mental check list of attributes that I am looking for in individual parent plants. In approximate order of importance from most important to least is:
- Interesting colour, beautiful shape. This is slightly vague because colour, and beauty, can jump around a lot from generation to generation. For instance, crossing a pure white with blueish red (both herbaceous hybrids) may not sound particularly interesting with probably many doubtful pinks, but such a cross, I have found, can throw pure whites and true reds as well as all those unwanted shades. Similarly, beautiful shape is serendipitous because many different elements make up beauty.
- Strong stems
- Sealed buds
- Reasonably productive (which I tend to correlate with healthiness – but not necessarily)
- Large size of flower (I tell myself that flower size is not especially important but there is a definite preponderance to larger flowers in what I choose! )
Ideally I want the parent plants to be strong in all features but of course they often aren’t. My golden rule for deciding on a cross is that a weakness of one attribute in one parent must be matched by strength in the same attribute in the other parent. In other words, I would never want to cross two parents that are both weak in, say, stem strength, i.e. both flop when open. If I did, it would have to be for some other very compelling attribute.Regarding colour, I tend to think in a colour blending sort of way i.e. I tend to pick parents in a population of similar coloured flowers. I guess I am hoping for additive effects in some of the offspring whereby each parent adds more than its 50% of the colour to bring about a stronger colour in the offspring.
Yellow herbaceous hybrids have a true but light shade of the colour. If you cross them and look at enough offspring, hopefully a few will have stronger colour than either parent – which I have found to be the case. As I illustrated above, though, crossing unrelated colours can produce a whole spectrum of results and I think this bias of mine to cross like with like colour has been somewhat unimaginative.
In my earlier years of hybridizing, I was interested in crossing lactifloras (diploid) with tetraploids, undoubtedly because of the quality of the lactiflora flowers. The biggest effort I did was with Good Cheer pollen (tet) onto Mikado (lacti), a repeat of the cross that created Christmas Velvet. I found it yielded one good seed per 7-10 pods pollinated. Of the approximately 120 seedlings that I grew, about 5-6 (from memory) were double and worthy of further consideration. In other words, useful yield was low. All of the seedlings were sterile, i.e. I have never seen a seed produced, and are presumed to be triploid. Other presumed triploids produced were from the use of Old Faithful (tet) pollen and yellow tetraploids, including Lemon Chiffon. Although pleasant, none of these latter crosses had any special virtue and I have now lost interest in triploids. The main reason for this is that it is essentially a dead-end laneway. I do not have a population of seedlings as I mentioned earlier, with which I can cross for another generation
Similarly, after meeting Peter Waltz when he visited New Zealand on holiday, I have tried to use triploids as pod parents with tetraploid pollens. Despite many efforts, involving large numbers of pods (100+ in any one year of, say, Etched Salmon) and trying out many different tetraploid pollens in a bid to find the more fertile tetraploid pollens, yield of viable seed was extremely low. I only ever got one seedling off Etched Salmon (completely non-descript and unhealthy) and although I got about 15 seeds that looked good off Coral Sunset, none ever grew. (I plant seeds in the ground.) Obviously I was chasing colour in these crosses. I have found it quite easy to get salmon colours but Coral Sunset has a vividness and inner glow, plus a wonderful change of colour in the cut flower as it ages, that has been hard to find in the tetraploid seedlings I have generated.
With these experiences in mind, I stick to working with tetraploids. I think there are plenty of suitable doubles to choose from, they are very fertile, and more vivid stronger colours are starting to appear. Some shapes, such as the Red Charm type of bomb double, are not readily available in the tetraploids I have, but I have proved to myself that Rubra Plena is fertile with tetraploid pollens.
Well this has been a little lengthy, but I hope it conveys an idea of how I think about peony breeding.
Paul Simmons
Simmons Paeonies, New Zealand
Thanks for sharing your experiences. I found this to be a very interesting read.
Dear Bob
Thank you for your comments and for taking the time to write them down. It is certainly nice to know that there is another soul or two out there interested in peony hybridising. Sorry about the delay in replying – I’m afraid I’m very low tech and especially hopeless at typing ! In the mean time we’ve had another flowering season ( always beautiful ) with cutting flowers and trying to breed peonies – they’re not particularly compatible activities.
Some comments on your comments. I think 100 plants from any given cross that you are seriously interested in is a good number – I aim for that – and that should more or less tell you what the cross can do.
I muddle along with reds too, except I have had difficulty with fertility i.e. with getting seeds. I have also struggled to get nice sealed ( non cabbage ) buds. Basically most of my reds have The Mackinac Grande in them but I find TMG not very fertile and very slow to germinate i.e. seed will be sitting in the ground for several years.
Digging on strict rotation must be a bit frustrating. I hang on to mine for ages and struggle with all the plants to care for! They do build up in numbers and there is probably some happy management medium but I’m not sure how you decide ! However this year I did strongly notice how much difference develops between year two, three and four. Some things at year two didn’t look particularly interesting but became much better at year three. The stems seemed stronger and the flowers so much bigger and more impressive! The other benefit of seeing older plants is seeing a bit more of their susceptibility to disease. This year we had a particularly bad season for Xanthomonas ( a bacterial blight ) disease in the peonies. I think we have definitely proved this year that the disease takes off after getting late frosts. Won’t go into all the details. However it was also clear that the disease builds up in older fields, i.e. in plants that had been planted earlier , say four or five or six years ago and that the earlier flowering tets were more badly affected. Although it was a bit depressing I guess we want to know which plants are more disease resistant.
So thanks again for commenting.
Paul Simmons
Did I forget to say "unique and beautiful" as goals? Yes, just like your Christmas Velvet seedling!
Dear Theresa,
Thanks for your praise of the christmas velvet seedling. I’m glad you like it. It’s not particularly fast growing but it’s not too bad. Size wise it’s about middle of the road! The bud is nice and it is adventitious budding, making it very easy to propagate.
When I first started to grow lutea hybrids I remember being disappointed at the side hanging posture of the flowers – but the plants were very little. However as they get bigger it seems to matter less and less and as you say – they still make a good show of it.
When I saw the wonderful colours in those first tree peonies it made me seriously wonder about the worth of what I had done ( i.e. hadn’t done ) breeding herbaceous ones! So good on you for cracking on with tree peonies.
Paul Simmons
Your Christmas Velvet seedling is absolutely beautiful, I hope it passes your test. Sorry to hear all your efforts for early white led to disappointment in a promising cross. It makes me think of "nicks" in horse breeding. Everyone is looking for that combination of bloodlines that will create champions.
Years have gone by without me being serious about peony breeding, but lately there have been some intriguing seedlings. Nothing as beautiful as what Nate Bremer, Bernard Chow, and the Southerlands have been putting out, but interesting and within my current goals. The goal of rebloom is no more: most of that breeding are gone and Japanese beetles eat the late flowers. Currently, the goal is upward facing lutea hybrids. Does this goal really matter? Looking at the plant habits of tree peonies, it is obvious most bloom outwardly rather than up and still make a good show of it.
Now that I can get a senior discount at some retail/restaurant establishments, age is a factor for me as well. Bill encouraged me to commit to untested seedlings, as he committed to using his favorite, Rosalind Elsie Franklin as soon as she bloomed. I am now taking his advice and moving into advancing generations with untested parents, though there is not much seed from any given cross.
Current goals:
1. up-facing
2. floriferous
3. yellow
4. clear color, whether single color or blend
5. semi-double and double (though I’m not tossing a nice single)
6. large flowers
7. tall plants (I’m too old to bend over so much!)
Dear Paul,
It certainly was a pleasure to read your article. Hybridizers often work in semi-isolation it seems, so it was interesting to see how many conclusions that you and I share. As you said, wonderful looking seedlings don’t always look as wonderful as they first did, when we originally saw them. "Advanced selections" from seedling beds, when grown from divisions can sometimes cause a person to wonder if the right plants were dug, or what it was that we saw in them in the first place. This is not always the case (thank goodness) but it seems to be often enough.
Like yourself, I have the looming feeling that time is short, and will try and bring promising seedlings into my breeding program as fast as I can. While it might be more prudent to wait until such seedlings have proven themselves, I think we’ve both seen the often-surprising variety that can come from even the most well-considered crosses. I consistently get a few pure white flowers when using the pollen of Old Faithful, which goes to illustrate something or other.
I’m afraid I fall victim to the "magic cross" idea sometimes, in that if I’ve produced a seedling that seems intriguing, I tend to make a whole lot of identical crosses using it’s pollen. There have been several instances where I’ve grown out over100 seedlings of a single cross, simply out of curiosity for the variety of results I might get. Often these crosses will involve pollens from the sorts of rare triploid x tetraploid seedlings you mention, as like yourself, I’m always trying to produce those as well. One other benefit from making a large number of identical crosses is that I can somewhat-reliably tell myself that I have indeed gotten a pretty fair idea of what that cross can do, what sorts of interesting trends may show up in it’s seedlings, and whether it’s really a cross that’s worth doing again or not. Which sometimes it is.
Each spring it’s always my planned intention to make certain crosses, and sometimes matters do come together where I’m able to do that, by using the mature plants I have at my home. But since my seedling beds are 150 miles away, like yourself, I also do a lot of "on the fly" hybridizing as well. While I’d rather be more well-planned-out with such crosses, I’m often forced to use whatever presents itself when I have limited time in the fields. And plan on "variation" to save the day.
As to hybridizing priorities, I seem to be putting strong stems at the head of the list more and more these days. When it comes time to do selection in the seedling beds ( the nursery digs on a strict rotation, so it’s do-or-die when selection time rolls around ) there can be a lot of plants, we often don’t have much time to consider them, and we end up going down the rows quite rapidly. In almost every instance I find that stem strength is the first thing I find myself instinctively paying attention to, as unless there is something truly exceptional about a flower, I know in the back of my mind that although there are a lot of variables to consider, seedlings with poor stems are likely to find their way to the compost pile sooner or later. The nursery is a big operation, and often it’s a long way out to the seedling beds, and one passes through many rows of classic varieties along the way. As one walks, it becomes hard to ignore the fact that hybrids which have stood the test of time generally all have good stems.
Saving plants to use in breeding is often another story though. Again, I’ll favor plants with impressive plant habit, parentage which seems promising, and if I’m using it as a pod parent, carpals that will indeed make seeds. In instances like this, often the nature of the flowers themselves sometimes seem to be my last concern. That said, it’s difficult to resist using pollen off of flowers which are "intriguing". Even plants with bad stems can produce seedlings with stems which are good, but they’d better have a flower of some very specific interest, or I’m unlikely to use them.
As you may have seen, sometimes there is some predictability to our crosses. I’ve produced some rows of whites myself, using pollen from promising white varieties on mother plants which are not always so white. Lemon Chiffon seems to produce a lot of yellows if it even looks at anything else with the slightest hint of yellow in it, or if it looks at anything of any other color for that matter. In all my efforts, I may have produced one seedling that has yellow which is a bit deeper than that of Lemon Chiffon, so it’s encouraging that you are finding some success with that.
Nice reds seem to be a thing that I’m still fumbling around with. Crosses which by all rights should produce good reds produce muddy or purplish reds instead. I suspect there are ways around this, but I still have some ways to go with my own efforts.
In any case, it was wonderful to read about your experiences, and to read about them here on this site. In the past hybridizers seemed able to keep in touch, so it’s sort of surprising that in this high-tech era, we still seem to be looking for a good location for that.
Bob Johnson, Oregon, USA