FAQ: Hybridizing Dahlias- Advanced

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Table of contents
» long term breeding strategies
» Dedication, Skill & Luck in equal measure
» Current color and blend trends for dahlias
» Seed/pollen parents for breeding
» petal pigments
» Breeding for cactus forms
» Breeding for lacinated form
» Breeding for purple
» Breeding for giants
» Breeding for stems
» Breeding for dark foliage
» Breeding for waterlilies
» Sports/transponon genes
» genetic oddballs
» virus in seedlings
» Dahlia Pollination
» Saving Pollen
» Hybridizing Articles
» Breeding for Stellars

long term breeding strategies
The best place to start with any new project is research. It is helpful to understand background information and what other folks have done, are doing, and why they are doing it.

The comments on this page is focused on details of other hybridizer's strategies and discoveries, which will assist new hybridizers to develop their personal long term breeding strategies.

teddahlia wrote:I believe that "line breeding" is when you cross seedlings back with their parent(s) or siblings. When you are breeding diploid plants(dahlias are not diploid plants), line breeding allows you to get homozygous strains of plants that have certain traits. You remember that term from your Mendelian genetics class in biology? Two genes are on each chromosome for each trait. Remember dominant and recessive? If the genes are different, one might be dominant over the other and the organisms will exhibit the trait of the dominant gene. The purpose of line breeding is to get the two genes in the diploid organism to match up(homozygous) so that the subsequent generations will all have that same trait. You are getting rid of the "bad" genes and concentrating the good ones and when you do that all of the progeny will only have "good" genes.

Since dahlias are octaploid, each trait has 4 pairs of genes and it is nearly impossible to get all eight of the genes to be the same one. And probably there are 3 or 4 different genes that fit on those eight locations making it even more impossible. But having said that "line breeding' is still very effective in concentrating good genes and eliminating bad ones. In octaploid plant breeding, it is sheer numbers of seedlings that ensures success. The genes will line up but it takes lots of crosses to do so. And in order to concentrate good traits you need to cross plants that have the same genes for the same good traits. What I am trying to say is that in dahlias there may be several ways to combine genes to achieve a trait. So, for example you may have two varieties with near perfect semi cactus form but they get that trait from a different set of genes. So if you crossed these two perfect semi cactus plants the results would be chaos and the seedlings would be unlike either parent. The way around that is to line breed and concentrate the same good genes in the seedlings. These genes are compatible and the seedlings much more consistent. So does Lexa get it's nice incurved cactus form from the same genes as the Hollyhill varieties? If you think so, it would be a good cross. .

Dr. Hammet calls the "random" breeding that most people do as breeding "mongrels" . People will select two flowers that are the same form but are totally unrelated and expect good results. If they do get a good one, it is by pure luck and the next generation of plants will be no better and probably. worse. A mongrel produces poor seedlings. Dick Parshall chose to continue the line breeding of Gordon Leroux. He used the numerous Kenora semi cactus flowers as seed parents and does not generally bring in other unrelated varieties. He does keep the best of the seedlings to improve his "line". He has been very successful.

Having extolled the virtues of "line breeding" it should be pointed out that many if not most dahlias have been achieved by random breeding of unrelated parents. It is the percentage of of "good ones" that line breeders are trying to improve. In random breeding perhaps one good one will result from 1000 seedlings. In line breeding,there may be 10 good ones out of 1000 seedlings. That means in the long run that you will have many more good ones. And my definition of "good ones" is probably different. For me the only thing that is good would be in this example would be a good semi cactus. The random breeder accepts anything that looks good to him or her. Perhaps, that is "more fun" than line breeding.

Margaret and I enjoy the randomness of collecting bee pollinated seeds from non Hollyhill varieties. They probably have been pollinated by a Hollyhill pollen parent as most of the pollen in the garden is Hollyhill. Those seedlings are very interesting. So there is quite a bit of "line breeding" here and lots of random breeding too. It is all fun.

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Dedication, Skill & Luck in equal measure
teddahlia wrote:If WLs, Poms, Giants, B and larger FDs, Balls, Stellars, Miniature cactus, Miniature semi cactus, Miniature IDs, micro anything, anenomes, are all hard to breed, I wonder what is easy?
And when you add to the list that purple is very hard as is light pink along with bicolor, a non fading red, a saturated yellow, a white that does not burn and picotee anything.

So conversely what is easy to breed?

Benny101 wrote:wow there is not even an easy answer to that question ,
I could change the entire operation over to A & B sized ID's and probably churn a few out every year but that is pure theory .

I want to work on the hard projects where the market is not so saturated , as Dr Hammett says in his book a good breeder looks at the market for " what is missing "
Luckily I am young and have many seasons to work on such projects . We work with many blush and bicolor varieties . With the number of purple , red and white dahlia grouped together here it would not be hard to guess at the desired results .

Having actual programs and trying to create entire lines of genetics for your own future use is a lot of hard work , I get a new appreciation for it every day as one is reminded at how much there is to learn and do but the satisfaction is immense . Yes we have all heard that story of a casual seed collector getting lucky but the family's and individuals that set down entire lines of genetics have to have a mind numming number of hours into such a venture .

teddahlia wrote:Lots of luck involved in breeding dahlias. Many Giant dahlias were seedlings of B sized flowers. It takes a lot of luck for that to happen. Lots of big time show dahlias were the result of a seed pod with only one seed(Zorro, Spartacus and others). Lots of luck there. Some people like PNWGal get lucky with their first batch of seedlings. Bob Hanley's first batch of seedlings were the only really good ones(lots of giants) and he thought it was too easy. He lost most of them because he had not been growing dahlias very long and because he did not know which ones were good and kept the wrong ones. He was never able to get any more giant seeds that were any good.

Benny101 wrote: Seems luck plays a major roll if you sit back and ponder it a moment .
Say four of us crossed the same two dahlia then it stands to reason we all have an equal shot , and since this is purely fictional let's say all four individuals get a 50% germination rate . All four of us have different experiance levels and set up's , yet At this point there is no advantage it is all luck .

Attention to the details and variables seem to be key , if you breed the most beautiful dahlia ever and do not recognize it or fail to keep the tubers it was all for not , flexibility is also a virtue , if you have some special hand cross you are dying to try it is not uncommon for mother nature to through you a curve

teddahlia wrote:"Say four of us crossed the same two dahlias..." There are a couple of factors that are not in the realm of luck. The person with good gardening skills would collect the seeds and get them to germinate. He would be familiar with how to grow dahlias and would get them to maturity and then be able to evaluate them. He would be familiar with the current dahlias in competition with his seedlings and would be able pick the ones worthy of growing another year. He would have enough skills to harvest and store the tubers and to get them to grow a second year. So without gardening skills and without familiarity with current dahlia varieties, the grower would be at a huge disadvantage. Thumb of 2016-06-22/teddahlia/3147c4

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Current color and blend trends for dahlias
teddahlia wrote:
When it comes to color of the seedlings, it is nice to know what colors are in demand. We all have our favorite colors and it is very easy to ignore colors that do not appeal to you. I try to pay attention to what others want and even though I may feel that some of the popular colors are not my cup of tea, they do need to be kept.

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Seed/pollen parents for breeding
teddahlia wrote: As we breed show dahlias we are making seed production decline. Show people want tight centers. Those centers are where the seeds form and when you reduce the size of the pollen center, you reduce the potential number of seeds. And furthermore, seeds need some room to form in the pod. Those tight centers have very little room for seeds. And it is worse for giant dahlias as they have huge seeds and need lots space to develop. And it is very hard to get seeds from poms for the same reasons, tight centers and very little room for the seeds to form. And it is even worse for the poms as the pollen centers that do open are too small for the bees and other insects to access. If you were a bee and you could get lots of pollen from a bigger flower, would you bother with a dinky pom? My wife hand pollinated some poms and got many more seeds than the bee pollinated flowers. So there is a conundrum: You want seeds to breed better dahlias, but the seeds you can get are from inferior dahlias.

And that is why we spend so much time sharing the names of varieties that make some seeds AND make nice seedlings.

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petal pigments
petal pigments intro

Ted, could you please edit this intro post and put an appropriate blurb here about the importance in understanding pigments when hybridizing with a color goal?

Could you explain the ADS color chips, too?

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Breeding for cactus forms
teddahlia wrote:Cactus and semi cactus seem to be caused by the same genes. Cactus are as they say just a bit more revolute, perhaps just more cactus genes. For some reason, I like semi cactus, cactus and incurved cactus more that the formal decorative larger flowers. One thing that we(Margaret is just as much involved as I am) look for is the depth of the blooms. Show people like the depth to be approaching the width in semi cactus and almost that much in cactus. And the other thing is the trait that every floret need to be placed exactly in the correct spot on the bloom. This trait seems to pass on to future generations. Hamari Accord is one of the most perfectly formed varieties as far as petal placement. Narrows Tricia is a seedling of it and it has that trait too. HH Goldrush is a seedling of Tricia and also has impeccable petal placement. I have been waiting for the perfect time to post this picture of three BB sized dahlias. They were shown by Christy Parks in a category that called for three different BB sizedflowers. HH Goldrush has the type of semi cactus florets that many judges like and that is that they are broad at the base. Both Embrace and Lakeview Glow have petals that are narrow at the base and narrow is fine for cactus but not so good for semi cactus.
Thumb of 2017-01-02/teddahlia/69c997

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Breeding for lacinated form
teddahlia wrote:There is no one that is specializing in breeding laciniated dahlias like there used to be. Jack Vandamant who I never met was going great guns until he had health problems and had to quit. His Colwood intros were excellent. Just a quick reminder: Cyril Higgo of South Africa was the guru of laciniated flowers and not only introduced many(some through Phil Traff and many through Les Connell) but also did something that no other hybridizer has done to any extent: he sold really good seeds for laciniated dahlias. You could buy a pack of seeds from South Africa and instantly had a couple or three show quality laciniated dahlias ready to name. The Tioga laciniated dahlias were one example. Most of the laciniated flowers out there now trace their roots to Higgo genes.

When we were still growing laciniated types, we used Nenekazi, a Higgo intro( I believe a tribal princess) as a seed parent and got HH Miss Scarlet and others. No more laciniated dahlias are allowed in our gardens as split tips on florets is a fault and the pollen is very dominant for this trait. I have a theory that the amount of laciniation is regulated by how many genes you have for split tips. Perhaps one gives you slight notching and two deeper notches and three even deeper until with many genes(up to 8)the ray floret is split all the way to it's base. I had a seedling that had florets nearly 3 inches long and were split nearly all the way. For the breeders of laciniated types, there are a couple other traits they want for laciniated flowers. They want the florets to twist at the tips to give what was called "fimbriated" look. And they also like the florets to be long and skinny and that is why they say a cactus flower that gets the laciniated genes is best. When a formal decorative flower gets the laciniated florets it looks quite different and the judges do not like them.

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Breeding for purple
need to cut/paste ted's blurb on most purples historically not storing well

teddahlia wrote:It may have something to do with the pH of the tuber. In order to have a purple dahlia, the pH is alkaline. Maybe the tuber is not acidic enough to keep pathogens at bay.

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Breeding for giants
teddahlia wrote:Isolating the Giants for breeding. Giants are the most difficult to isolate AND get seeds. With all the other types with the possible exception of Poms, if you isolate the plants you want to cross with each other, there are many flowers showing pollen. With the giants there are very few if any such flowers in the isolation patch and if the flowers get pollinated it is from pollen further away. While I have no proof of this hypothosis, here are some facts. At Wyn's Dahlias they grew nearly all giant dahlias and yet the great majority of their seedlings were much smaller. They did grow some B sized flowers and kept some of them to sell and I bet lots of pollen was available for bees. And I am sure that since they said that most of the seedlings were smaller that the pollen from those smaller seedling flowers was harvested by the bees and pollinated the giant flowers. Margaret and I successfully hand crossed some giants and the seedlings were much larger than "field run" giant seeds. Moonsong, Clydesdale and Big Pink were all hand pollinated seedlings.

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Breeding for stems
teddahlia wrote:Stems: breeding new dahlias is a lot easier than it used to be because modern dahlias have nice stems. I have avoided some old timers for this reason, specifically Thomas Edison. It has great color and floppy stems .Look at old time pictures from the 1920s and the dahlias are all bending at the stem as the stems were terrible by our modern standards. When Jersey Beauty came out in the late 1920s, it had excellent stems. It went on to be the most financially successful dahlia of all time as tubers went for $25.00 each.

When one talks about stems there is the show dahlia version and the cut flower version of stems. They are very different and that is strange to the average person because we are talking about the same flower from two different perspectives. Show people define the stem as the stalk from the flower head to the first set of opposing leaves. Flowers must be shown with at least one set of leaves(and two in some places but not here) and the stem needs to be long enough for utility and beauty and strong enough to hold up the flower and straight enough to look good. So a long, straight(very straight, exaggerated straight to really win much) stem is needed for show entries.

Cut flower people could care less about leaves on the stem and the definition of a stem only being down to the first set of leaves is irrelevant to them. They want a long stem and that includes the stalk all the way down on the bush with any number of sets of leaves. They want it to be as long as possible(well, past 24 inches would be unusual) and strong enough that it does not break in the wind or in the flower handling process. And one of the mortal sins of stems is "bobble head" dahlias where the flower is not firmly attached to the stem. The old florist adage is that you can cut a stem to length but that you cannot add to a stem. So they want long stems to start with and cut them to length for the type of design. I have seen a florist take a bundle of ten dahlias with 18 inch stems and chop them down to a bit more than 6 inches for a design.

So, when you are breeding dahlias you need to make sure the seedlings have good stems for the proper purpose. It is probably a more critical factor for cut flowers than for show flowers but both need good stems. And of course, if you use seed parents that have good stems, the seedlings generally will have good stems. So, when I said that the new one at the trial garden had good stems that were 24 inches long, that was a supreme compliment.

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Breeding for dark foliage
teddahlia wrote:There has been lots of speculation on the mechanism of dark foliage. I believe the consensus was that there are multiple genes that can be accumulated to make plants a darker shade of red tones. If a plant only had one or no genes, it would look normal. If more genes lined up and were in a seedling you would see some darker stems. If you have a full compliment of genes the foliage would be very dark red. However, they figure that at least one other gene complicates things and helps or hinders the red trait. In other words, the exact mechanism of the genetics is unknown. Since Dr. Hammett "specializes" in breeding dark foliage dahlias, I am sure he knows more than most people about the genetics. Since it has been a commercial venture to create the dark foliage varieties and they get patented, I bet he is not sharing the information. If you want dark foliage seedlings the oldest trick in the world is to use the dark foliage ones for breeding. It is just difficult to get very many and the darkest ones are very rare.

Benny101 wrote:Are there any fully double varieties with dark foliage that grow taller than 24" - 30" ?

teddahlia wrote:There are/were lots of them: David Howard, Purple Flame, Engelhardt's Matador, some others by Dr. Hammett. Remember dark foliage could be rated on a point system where 10 is the blackest and 1 has almost nothing. Dahlias with 8 or 9 are fairly common but 10s are very rare.

FLflowerboy wrote:My AC Hwy 61 is almost three ft tall and has beautiful burgundy foliage. Ken's site photo does not do the bloom justice. Blooms alternate colors very regularly. Blush white, then red, then bi-color. The blush color reminds me of CAL, so it looks intriguing with burgundy foliage and some blood red flowers all blooming at the same time...because the bi-color is white and red with no blush of pink to be found.

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Breeding for waterlilies
Benny101 wrote:Is it common to get somewhat open centered seedlings from WL ? Or maybe just not enough developed florets to produce a fully double ?

teddahlia wrote:The majority of WL seedlings are open center. That shape is not easy if you think about it: Not very many ray florets and they must also cover up the pollen center. WLs are very frustrating.

Benny101 wrote:WL are a bit shallow by nature and every floret has to be in just the right place .
I saw a little of that last year but have many more WL seedlings this year . Knowing that is normal is a relief .

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Sports/transponon genes
Sports/transponon genes

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genetic oddballs
genetic oddballs

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virus in seedlings
teddahlia wrote:If the parent of a seedling has virus, a small percentage of the offspring can be infected. Wayne Holland used a very virused seed parent(there was no healthy stock available anywhere) to produce many of his famous introductions. He pointed out that he needed the genes to produce the petal shape he desired and that tossing the infected seedlings was easily done.

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Dahlia Pollination

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Saving Pollen
Saving Pollen

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Hybridizing Articles
Hybridizing Articles

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Breeding for Stellars
teddahlia wrote:Dick Ambrose of Camano Dahlias(a high school math teacher) explained how the stellar form started. Breeders for many years had been culling flowers with pointed petals or petals with center folds or grooves( ala stellar). That is because formal decoratives are supposed to have rounded petals and no grooves. His origination Camano Pet was being shown in the formal decorative class and despite it's unbelievably well placed florets was not winning best. When it did win, other judges complained that it was not a true formal decorative flower and lots of arguments ensued. Someone noticed that the flower Alloway Candy had many of the characteristics of Camano Pet , specifically long pointed florets with grooves or troughs and the florets curved back mostly to the stem(but not all the way). The light bulbs went off and they decided to create a class that would include both of these flowers and any others of similar form. I believe the name stellar refers to the way a star twinkles or something like that. They went about writing a standard for the new class. The next year Camano Pet won everything and Alloway Candy was left in the dust. They decided that the standard had to be re-written and came up with the novel concept of "negative space" . It was explained that the there must be space between the florets to express the stellar form. Why it is not called positive space makes no sense to me. The next year Camano Pet was shunned from the head table by judges who determined that it has "no negative space" . And so it goes. Camano Pet is one of the best show flowers without show class for it and Alloway Candy was declared to be the "ideal" stellar flower and seldom wins best stellar. Meanwhile, breeders have come up with some good examples of stellar flowers. I am not much of a "stellar" fan and am not breeding for the form but some seedlings do seem to look like stellars and so get kept for another look.

How do you breed them( or avoid breeding them in my case) ? The golden rule of dahlia breeding is to cross flowers of similar form with each other to get that form. I can make sure they are not in my garden and then few stellar seedlings will occur and that is good for me.

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