As a general rule, my known 'early' bloomers (Patty Cake) bloom in May/June. Known late bloomers (Baarn Bounty) start blooming now. But why would an early dahlia also bloom LATE?

I bought Tomo from a box store 4-5 years ago. It was always the first (or one of the first) bloomers. Couple years ago, I divided (the many) tubers and lazily planted a couple near the main plant.

Last year, the main plant bloomed in May as always but in August, when it was dying down, a 2nd bush started blooming. It was Tomo (2) - just where I had planted one of its offspring. So again this year, plant 2 has 3-4 unopened buds on a small bush and is getting ready for another late summer run.

How could the same variety be both an early AND late bloomer? Last year it bloomed into October and while this is EXACTLY what I like in a dahlia (blooms for 5-6 months) I am perplexed why it does this when it they are within 3 feet of each other and obviously get the same water, food, sun, soil etc.

Anybody with a thought? Or anybody have the same thing happen? Anybody know what makes them early versus normal versus late bloomers to begin with? I would think plant DNA but then how to explain my Tomo(s)?