I haven't grown it personally, but it gets excellent reviews, with most vendors commenting n its floriferousness. And it's grown in SoCal zone 10 so can certainly tolerate heat.

I wouldn't be overly focused on the winter chill aspect. Since it grows and flowers in a zone 10 with an even milder winter climate, there is no reason to suspect it wont do so also in your zone 9b.

Here is a previous discussion on this rose: https://www.houzz.com/discussions/3500097/any-experience-with-florentina-kordes-climbing-rose

btw, since a zone 9b has an average winter low temp of 25-30F - below freezing - you DO get winter chill!! Just not a great deal of it :-)

@gardengal48 (PNW Z8/9) Thank you for the encouragement. I am a bit concerned having 4 Florentina as the 2 I already have are not prolific grower/bloomer despite everything I did for them. I babied them like my other roses but they don't seem to give me anything in return (yet), lol.

We rarely get that 25-30F temp here, and even if we do, it's probably only for for few days.

Winter chill hours are calculated on the time spent below 45F. That is just not a factor here.

@sharon2079 Sorry to hear about your chilli thrips :( Do you have any pictures of your Florentina? :)

I was interested to read that most entities seeking to sell Florentina comment on its floriferousness.

This rose Can take a couple of years with minimum bloom to get going.

@Vaporvac Z6-OhioRiverValley I heard that too, but since mine was in a 3-gal pot, I thought they are somewhat mature enough to at least give me a few blooms this year 🤷. The new 1-gal ones I got at Lowes seem to be growing faster than my 3-gal though, so I may just keep all 4.