A temperature / weather-controlled effect?

On a Saturday walk through an urban rose park, I was delighted by a bloom on ‘Persian Yellow’ that was completely unexpected for me for this time of the year. My ‘William III’, which is also a once bloomer, is just starting off on a third blooming.


Did you snag some pollen for the freezer?

Flowering is indeed controlled by temperature though it’s complicated.

# Phytochrome control of flowering is temperature sensitive and correlates with expression of the floral integrator FT


Thank you very much for advice and link. Unfortunately I have not been able to snag any pollen, because the opened flower was too high to get to. Surely the pollen would also have been overripe already. In addition, the rose park was very well visited to do various efforts. But I have the remaining lower buds in view and will try my best soonest possible.

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R. Xanthina is “repeating” for the fourth time here this year. We got “hot” then it cooled and I’ve been copiously watering. Then, this today…