Question: What can one expect to gain by having a "marriage" of a modern day, daylily cultivar and a species daylily? What are some of your suggestions for the parents that a person could use in order to achieve the specific results? I am aware of a lot of sources for modern daylilies. Are there many sources for the species plants? Many thanks, Jack
Answer: Jack, you sure do have a way of asking questions that can't be answered in a simple, straight forward manner! The answer to your question really depends to a great extent on what you want to do with your daylily hybridizing. If you want to compete with the big named hybridizers, then going back to the species will probably only slow you down considerably, although there are some long term factors that you would need to consider. If, however, you are interested in exploring the daylily germplasm base and having fun without having serious considerations of commercializing your hybridizing efforts, then going back to the species can be rewarding. Before going into the details of answering your question it will be necessary to give some background information on daylily species, hybridizing and the daylily society.
Daylily hybridizing started over a hundred years ago with the first hybrid being introduced in 1897. For the next twenty years or so most of the hybridizing centered around using the species and hybrids that were close to the species. The species used in the earliest years were H. middendorfii, H. dumortierii, H. minor, H. multiflora, H. thunbergii, H. citrina, H. altissima and H. flava, with H. aurantiaca and H. fulva rosea being added later. The earliest hybridizers had to use the species because that was all that was available. However, as newer hybridizers came aboard they didn't have access to the species and instead started out using the hybrids. By the early 1930's there were probably few hybridizers who were using the species with the exception of H. fulva rosea and maybe H. aurantiaca. In the early years of daylily hybridizing you had a choice of two colors - yellow or orange. However, the use of H. fulva rosea and H. aurantiaca introduced red and pink into the daylily germplasm pool, which eventually produced purple and lavender daylilies while H. aurantiaca introduced the non-deciduous foliage trait, and a lack of winter hardiness, that eventually shifted daylily hybridizing from its northern and Midwestern roots to the south.
No one knows with absolute certainly just how many species daylilies there are because most of the species daylilies come from China and China has been pretty much a closed society for much of the 20th century and not accessible to exploring for daylily species. There seems to be a general consensus that there is between a dozen and two dozen species, while others claim up to three dozen. In the literature you will find many species names, but some of these are just synonyms for other species and some may actually be species that are no longer available in cultivation, but may still exist in the wild. There is also the question facing taxonomist as to just what constitutes a species. If you look at the literature you see a lot of plants given species status that in reality are only minor variations of an existing species. Not only were there relatively few daylily species used in the early years of hybridizing, those species that were used were represented by a very limited amount of clonal material.
The roots of the American Hemerocallis Society goes back to the 1930's with the strong interest in daylilies in the Midwest and the formation of the Midwest Hemerocallis Society. The AHS's goal is to promote daylilies in it's broadest sense, but you will find very little information about the species or daylily hybridizing in the Journal. This lack of information has been supplemented by the "lecture circuit" where well know and some lesser known hybridizers give presentations at various regional and local cub meetings, and by presentations at various winter meetings. The end result of this is to reinforce what I call the "Florida breeding syndrome" - the breeding of round and ruffled daylilies between 18 inches and 30 inches tall, with far too many newer hybridizers all using the same limited germplasm pool. These daylilies are quite beautiful and attract a lot of attention, but they are basically the same daylily in different colors, sizes, heights and with some other minor differences, and in many cases the resulting flood of introductions are so similar in actual appearance that it is next to impossible to identify them if you lose the labels.
The question you have to ask yourself is, where do you want to be within the hybridizing picture? If you want to be a big named hybridizer, or well known within your region, then you are going to have to hybridize what is popular, and more importantly, what will receive votes in the awards system. Trying to incorporate the species into your hybridizing program will set you back at least 10 years, or longer; but, if you make the correct crosses, you could eventually be successful. If you are just enjoying hybridizing as a hobby and would like to eventually make some contribution to the evolution of the daylily as a garden plant, then going back to the species can be not only fun, but rewarding in a modest way. There are several reasons for going back to the species.
First, we have to look at the overall germplasm picture. The modern hybrids are the end results of not only a relatively few species being used, but a limited amount of clonal material within the species. Some of the species such as hakunensis and coreana, and maybe sempervirens have never been incorporated into the existing modern daylily germplasm base while there are many other clones of the species that only became available in the later part of the 20th century and also have never been incorporated into the existing hybrid germplasm base. On top of that, consider the vast germplasm pool of daylilies in China that we know nothing about! What genes may these daylilies contain? It could be that the blue gene that some people think is the Holy Grail of daylily hybridizing exists within this unexplored germplasm base, or maybe resistance to the new daylily rust disease that may contaminate all Florida hybridizing. We won't know what potential lies within these unused species and newer clones of species unless we explorer this germplasm. The big named hybridizers are not going to be doing this. Exploring this vast untapped reservoir of genes could not only be fun, but may also result in vast new avenues of daylily hybridizing that don't yet exist.
Another practical reason for going back to the species is to recapture traits that have been bred out of the existing modern hybrid base. This approach can probably be accomplished with out too much loss of time. H. altissima can be used for height for those who like 7 to 8 foot tall daylilies, for exceptional branching for those who still like the shorter daylilies and for its nocturnal blooming. H. sempervirens, H. flava and the H. fulva complex can be used for recapturing the rhizomatous trait for landscape daylilies and for spider and unusual forms hybridizing. H. citrina and H. flava can be used for fragrance. H. hakunensis has nice branching and excellent flower senescence.
You may also want to consider going back to the species if your interest is in breeding daylilies for mass planting or naturalizing, or even if you are interested in the low end mass market. These are daylilies that need to be able to survive with minimum or no care after being planted, and many gardeners interested in low cost daylilies want daylilies that have a more natural look to them then the modern hybrids but don't want daylilies that have the coarseness that many of the species have. How then can you accomplish these various goals?
There are two basic approaches you can take with species hybridizing. The first is to make species x species crosses while the second is to make species x modern hybrid crosses. If your goal is to incorporate existing traits from the species or to quickly incorporate undiscovered genes from the species, then the easiest approach is probably to make species x cultivar crosses using cultivars of exceptionally good quality. The F1's generally are not impressive, although some aren't all that bad. What you do with the first generation seedlings will depend to some extent on what you want to achieve, but as a general rule you should try to make as large a F2 population as possible by intermating the better F1 progenies, or possibly backcrossing to the cultivar parent and then sibmating. What you are mainly aiming for is to recombine the species and cultivar genes while recovering as much of the cultivar traits as possible and the desired trait from the species. Self pollinating the F1 seedlings is also a possibility, but self pollination often, but not always results in a lot of weak seedlings.
There is no guide lines for what cultivars to use. Very similar cultivars when crossed to the same species can result in quite different F1 progenies. If your interest is in spiders you would think that it would be best to use a spider cultivar as a parent, but crossing the spidery species with round and full cultivars will easily produce ample amounts of spidery seedlings from near classic spiders to fat spiders. Many of the fat spiders from species x round and full are quite attractive.
The species x species approach is interesting for those who may be interested in daylilies from a more scientific side rather then as a commercial hybridizing effort, and for those interested in daylily genetics. However, there may be some interesting potential here for breeding daylilies for mass planting, naturalizing and possibly for the backyard gardeners who want a more natural look. Surprisingly, this can be accomplished with a lot less effort then some people think. For example I have a seedling from H. hakunensis selfed and then backcrossed to a different clone that resulted in a beautiful yellow flower that many people would refuse to believe is actually a species, yet alone H. hakunensis. Right now I am using this clone in place of the original clones of H. hakunensis I have, but eventually plan to offer it for sale. These daylilies are not likely to attract the attention of AHS garden judges, but could have some potential in the wholesale trade.
Of all the species, H. middendorfii and H. dumortierii probably have the least attraction for hybridizing, unless you are interested in very early blooming daylilies, and even then H. flava might be a better second choice as it blooms within two weeks of H. middendorfii and H. dumortierii while lacking the top budding and deep orange color of H. middendorfii and H. dumortierii. There is probably little reason for anyone north of Florida to use H. aurantiaca as H. sempervirens is very similar and winter hardy. Both H. minor and H. multiflora offer some potential, but I haven't used them very much. H. minor has some potential for those who want to breed very small pot culture daylilies. H. multiflora's greatest value would be in late blooming, but I prefer H. sempervirens as a source for late blooming because it combines with the modern cultivars much better and it also is a bud builder.
H. citrina, H. thunbergii and H. altissima are all closely related. I don't see too much reason for using either of the commonly available "early" and "late" forms of H. thunbergii as H. citrina is a much better choice. However, there are some newer clones of H. thunbergii available that are much more attractive and may be worth using. Of the three I prefer H. altissima. Although H. altissima is a small flower compared to H. citrina, it can produce hybrids with very large spidery flowers even when crossed to very round flowered cultivars and it is a much paler lemon yellow color that combines better with other colors then H. citrina. Another advantage of H. altissima over H. citrina is that it can produce much taller hybrids, if that is what you are interested in, the F1's tend to be quite fertile and the F2 generation can produce progenies with exceptionally nice branching while having all the desirable cultivar traits we like.
Both H. coreana and H. hakunensis are worth exploring because neither of them appears to have been used in developing the modern hybrid germplasm base. I'm particularly interested in H. hakunensis because of it's very desirable senescence trait which would make it desirable for mass planting. H. hakunensis is a bit course looking, but seems to be quite heterozygous for many good genes that only needs to be brought out by recombination. Intermating various clones of H. hakunensis can produce some quite nice seedlings.
The species that I am making the most use of right now is the H. fulva complex and H. sempervirens, which some people consider as a variety of H. fulva. I'm mainly interested in these for developing mass planting daylilies that are rhizomatous, but some of the progenies show little or none of the rhizomatous trait even when I am expecting the rhizomatous trait to show up. Some people may be interested in some of the various clones of H. fulva or H. sempervirens because when crossed to wide and round cultivars they can produce interesting progenies of the unusual forms class along with the cascading types that some people like. Both H. fulva and H. sempervirens seem to combine well with many cultivars and the F1's can be quite attractive. I no longer use the original form of H. sempervirens as I have a self pollinated seedling from it that has a much nicer flower form with a reddish color and lacking the fulvous color, but, importantly, it also produces unreduced gametes which makes it useful for breeding tetraploid spiders.
All of the daylily species are diploids, but that doesn't mean you have to hybridize with them at the diploid level. I suspect that all of the species will produce some unreduced gametes which makes it possible to make diploid species x tetraploid cultivar crosses and quickly incorporate species germplasm into the tetraploid germplasm pool. Some of these hybrids are quite fertile. One drawback to making species x tetraploid crosses is that the fertile F1's are strongly amphidiploid and it may be very difficult to get rid of undesirable species traits. The H. fulva complex probably produces more unreduced gametes then the other species, and it is possible, if you find the correct combination of species and tetraploid parent, to easily produce tetraploid seedlings by the hundreds. I also have some tetraploid x H. altissima hybrids, but so far they have not produced any seeds or been successful as pollen parents. Brian Mahieu has some H. citrina x tetraploid crosses that appear to be quite attractive. The use of species x tetraploid crosses would probably be most valuable for those interested in tetraploid spider and tetraploid unusual forms daylilies. However, many of the older diploid spiders are from H. fulva and H. citrina hybridizing and it is likely that many of these will be producing unreduced gametes, so it may not be necessary to go back to the species in this particular case.
Locating the species can be difficult. There are some private and public gardens like Longwood Gardens, the New York Botanical Garden and the US National Arboretum that have, or had decent collections of daylily species, but getting plants from them is almost, but not totally impossible. There are other botanical gardens in Europe and Asia that probably have species, but communicating and acquiring plants from them can be difficult. There has never been much of a strong interest within the AHS for growing or preserving the species. There are probably three dozen people within the AHS who have a strong interest in the species and most of them are not into selling plants. Because of the relatively limited interest in the species these growers only maintain a limited quantity of plants of each species. Many of these growers, are, however, generous and will share extra plants with others whom they know have a real interests in the species. Finding them will be the difficult part, and some are rather old or retired now. Apps has a few species listed in his catalog and I have some available at my web site (www.open.org/halinar/cbs.htm) but generally only have a very limited quantity of plants available, except for H. flava which is one of the few daylily species that has commercial value, and H. fulva rosea which also has some commercial success. My general advice to you, if you see a species you are interested in and it is available for sale, buy it and add it to your species germplasm collection. We need more people to grow and preserve the species so they can be passed along to future generations.