Do sunflowers breed true to type?

[CelticRambler]

Had moderate success with sunflowers last year, with two varieties of seeds bought ... somewhere. 29ct pack in Lidl for sure, and one other. Anyway, I collected the heads, made an effort to keep the two varieties separate, eventually forgot why they were in two separate bunches and mixed all the seed together ...

2021 - planted a load of seed and now have two, maybe three types. In the photo: left of pic, one past-its-best "giant" with a head about 40cm in diameter, classic homogenous sunflower yellow, one flower per stem; top right, smaller, multiple 10-20cm heads on one stem, wayyyyy taller than the other (see spiral tomato stakes for comparison) and a three-tone rust-orange-yellow colouration. The third type (not pictured) seems to be a shorter, all-yellow, single-head per stem flower of about the same size as the multi.



What I'd like to know is this: if I save the seed and label it this year according to the style of flower, can I expect it to grow true to the parent type? This would affect where I plant them next year.

[765489]

I've sunflowers too but they are only starting to head and flower. They pollinate with other Sunflower varieties so you may not have pure seed Celtic but might be interesting to see what the results are next year

[CelticRambler]

Sunflowers regress to smaller and smaller with each generation. Seeds for the 'giants' are selectively bred and they don't hold true.

This was what puzzled me, and prompted my question. This year's giants are gigantic - bigger than I've ever had before (bigger than I've ever seen) ; and the tall ones are taller than their parent plants sown last year. The two types were on opposite sides of the house last year (so that'd be a minimum 3m high solid barrier and about 30m horizontal separation) so there might have been some small effect on the possibility of cross pollination ... but I definitely wasn't expecting to see the characteristics of both types exaggerated.

Well, I'll keep the heads/seeds separate this winter and see what they grow into next year. Both types are wrong for where I originally wanted them to go, so if they do become smaller, at least I know they have a place for the future!