I’ve used Rosa setipoda for the first time, last spring. I collected 3 hips from Many Happy Returns in June amd now have just on 2 dozen seedlings.
I usually do not pot up until the seeds sprout in the 'fridge, and have become used to separating individual seeds when I do pot up.
Twice now, and only with this cross, I have had twins. Both vigorous, and easily separated.
Do roses throw twins? I mean, 2 embryos in one ‘seed’.
All the germinated seedlings are going great guns, very healthy, no problems with damp off. Sprout to seedling rate about 90%. (Wish I could say the same for some of my other crosses.)
Rod