How to increase Dahlia seed production?

Rahlia Could shaving the ray-florets (petals) and pollinating the ray-florets be helpful?

This is a method I was taught when learning to breed dahlias. My father would use scissors to cut off the ray florets to just above the stigmas and then brush these with pollen several times a day,

As mentioned previously, the most important thing to do is to pollinate the stigmas several times per day for several days. The stigmas are only receptive to pollen for hours, not days, so timing is important. That's why hand crossing is such a PIA lot of work.

Hand pollinating dahlias is a lot of work done properly. I personally won a medal with a flower I hand pollinated. It was the last one I ever did as it was too much work. Some people like meticulous time consuming tasks that give you rewards. Margaret has the patience and persistence and attention to detail to do it. I do not. There is a long list of breeders that tried it and quit. My favorite successful hand pollinator was the UK breeder, now deceased, Ken Stock. He explained the process in exquisite detail and personally had results that made people envious. Despite all the years of his successes and showing pictures on his website and entering in trial gardens, very few people became hand crossers.
Note: I am not allowed to share Margaret's specific procedures. If I did I would no longer be living in this house. She says they can read Kristine's book and there is enough info in there to be successful. After all , when Kristine visited our garden way back when , Margaret showed her how she did it.

SteveM

SteveM by only receptive to pollen for hours do you mean only a few hours per day when temp and moisture levels are ideal. OR only a few hours period/ a few hours total in the entire life cycle of that bloom? Like there is such a small window of opportunity and if you miss time it it’s just gone? I would wait for flower to open, flower to make pollen, then finally for the stigmas to look sticky if that makes any sense. Maybe some I did before they were looking sticky in “now or never” type of situations like I was getting ready to leave for a trip. Do all the stigmas go into “ready for pollen acceptance” mode at the same time? Or is it a staggered event?

Bessie

I had one dahlia bed that had afternoon shade. Another dahlia bed in a different part of my yard was in full sun. I would see tons of bee action in the sunny part of the yard and think “perfect time to do some hand crossing”. I would then make some crosses in both the sunny dahlia bed and the shady dahlia bed.

One plant I focused a decent chunk of time into crossing (ivanetti) was in the shady dahlia bed. I hand crossed it with 4 different varieties and it made me zero seeds. I’m wondering now to myself if this could be due to cooler temps during crossing since it was in the shady bed or if it just doesn’t make seeds, or if it just doesn’t make seeds with the flowers I tried to pair it with. In my mind bees out = good temps and timing for hand crossing. But I guess I should have thought about the different mini temperature zones within the yard.

However when those same crosses were reversed and ivanetti was the pollen parent instead of seed parent 2/4 of the other plants all located in the sunny bed made (what appears to me) to be pollinated seed.

Then again I’ve had this same scenario happen with my full sun plants I crossed as well. Cross a pair both ways so each one has chance to act as seed and pollen parent but then only one plant makes seeds. Maybe I’m in denial because I love ivanetti and wanted seeds from it. I will relocate all my plants to full sun next year and see if that changes anything. Also I’ve said before a good chunk of my crosses were not even close to ideal situations. Limited pollen, not repeating the cross multiple times, it’s my first year attempting this, etc. Soooo has anyone gotten seeds from Ivanetti ?

Ivanetti is one of the several sports of Cornel and it was hybridized by Cor and Nel Geerlings of the Netherlands. I am no expert on them but Cornel Bronze, Ivanetti, Isabel, Caitlin’s Joy, are some of them. For many years breeders shunned Cornel as a seed parent and I do not remember why but I tried it years ago and nothing came of the seedlings. Rivers Dahlias used it as a seed parent and got Rivers Yellow Snow. I have yellow snow but it's seed production is terrible. I believe Jowey Dahlias from Europe used Cornel in his breeding program and many nice flowers were released. I grew Joey Frambo and It was very nice but not a good tuber maker for me and I lost it.
https://library.floretflowers.com/products/dahlia-jowey-frambo

Comment: If a variety is a poor seed maker , odds are it will not be a good candidate to be hand pollinated and make seeds. Best ones for seed production are the ones that make lots of seeds. However, they are often not the ones you want to use as a seed parent.

SteveM oh that makes a lot of sense now. With the hand crosses I attempted a lot of the time when opening the seed pods there would be no seeds on the outer most layers and then seeds only near the very center. But all the videos online showing harvesting seeds with open pollination you see seed right on the outer most layers of the seed pod. Which makes sense because my timing was pretty random and I didn’t repeat many crosses multiple times or multiple days

Teddahlia I personally liked Ivanetti because it seemed so durable and productive compared to the other plants next to it. I assumed since Cornel makes seeds Ivanetti probably would also, or is this a toss up with sports?

Teddahlia I’m now realizing I should have used open pollination to get more stats on who makes seeds THEN use that info to go into hand crosses…more learning and ideas for me for next year I suppose

Teddahlia your info gives me breadcrumbs that fuel my hope of what might give me seeds.

Teddahlia I cannot think of any ball that make lots of seeds or even an average number of seeds

SB’s Ora was a slightly above average seed producer for me. (Haven’t grown any of them out though).

I was able to get a decent number of seeds off both Brown Sugar and Copper Boy this year.

I was discussing actual ball dahlias and seed production. Miniature ball dahlias make many more seeds for me and the ball seedling I got this year has a miniature ball grandparent and formal decorative parent. I have no problem getting lots of MB seeds every year. Having said that , I only use our own intros for seeds.(three are medal winners and all make seeds ).

SB Ora is classed as a ball I think, although it’s on the small side, in my garden at least.

For some reason ball dahlias are very difficult to bred due to their overly large size. Yes, I said they are too big for their britches as they have to be 3.5 inches in diameter and have the rolled up(involute) florets. That trait requires the florets to be very wide so they can roll up and that takes away from their length. A 5 inch diameter ball dahlia is a giant ball. Hilltop Ivan is one that can be that big. It is also pretty much extinct. Senior Ball was another one. The best sort of large ball in my opinion is Snoho Doris.

5 inch Snoho Doris entered by Christy Parks

I found out this year that I am not very good with hand pollination. It's almost impossible to do with two toddlers in tow and a full time job, especially trying to hand pollinate several times in a day in several days. So I'm going to have to try isolation bed or culling dahlias in the main dahlia bed and let the bees do it. Previously in this post, there was mention that the late Mike Iler had an isolation bed was about 100 feet. I've have also read a bed 10 feet away from other dahlias is sufficient. I acknowledge that bee pollination will not be completey reliable when trying to polinate a specific flower to another, but I'm willing to accept that fact. Some seeds from dahlias with the desired traits will be better than no seeds. What is the recommendation on how far the isolation bed should be planted from the main dahlia beds? I'd like to hear your guys experience with this.

"I've have also read a bed 10 feet away from other dahlias is sufficient." How the heck do they know? Did they do a 100 foot spacing and 10 foot spacing and compare results? Or did they just get a few nice seedlings at 10 feet and declare that to be a success? When I talked to the late Gordie Leroux my only time( he died about a year later) he said he removed all flowers from plants that he did not want to cross with his seed parents. Then he picked extra flowers of good ones and placed a "pollen" bouquet near the seed parent plants. If you do not have success hand pollinating, why not use his method? It is probably better than isolation beds.