What is your goal with crossing? If your plants made seeds, then they were more than likely produced sexually (from pollination). You'll be the envy of all your neighbors-starting drought-resistant dandelions! I just got a bag of seeds from Penn. dandelions. I'm hoping to grow them for salad greens here in Fla. We don't really have dandelions as I knew them from up your way; we do have a wimpy little one,kind of like it. Whenever I ordered "dandelion" seeds online, I always grew out blue flowered chicory, bur that's not what I wanted. Paul, Riverview, Fl.

The plant usually referred to as a Dandelion (Taraxacum official) does not reproduce sexually. Pollen is however required to trigger the production of parthogenic (asexual) seeds.

As a result, breeding experiments with them are very much unlikely to produce any interesting results... however, Dandelion clonal lines from different environments will have been selected for different growth characteristics which can make the project of collecting them from different places an interesting project.

The blue-flowered variety sounds more like Chicory (Chicorum intybus)

Thanks for your responses. Duly noted. I think that at least one of them may not be Taraxacum officinale, but not sure. I guess I'll find out!

I am growing French Dandelions "Thick Leaved". I want to let one or two flowers go to seed.
But I am afraid it will cross with the regular lawn dandelions in the yard next door. From what xenoblep just wrote, maybe I don't have to worry about that?
Is it possible that French dandelions will only produce French dandelion seeds? Or will they cross pollinate with regular lawn dandelions