FWIW my Vielchenblau isn't later, but it's in a dry-ish location facing west.

There is one difference in bloom time that comes to mind that's tied to the genes of the roses. Those from multiflora and from wiichurana seem to bloom along with their forefathers...early.

Those that came from or through Rosa setigera are a lot later. As is setigera a whole lot later than multiflora.

To confuse things, I have wondered if there are two setigera spp. out there. I've seen pictures of the more northern setigeras and they are huge. I've looked for that massiveness in our (Tennessee) setigera and I have yet to see it. The tallest setiegera I've seen anywhere in my part of east Tennessee is three feet.

I agree with Ann that bloom time is conditioned by the rambler's species ancestry, but am not sure about her examples. The 'Dorothy Perkins'-style ramblers are among the latest here, roses with ancestry in the musk group seem to run late (R. moschata and 'La Mortola' in my garden, and 'Crépuscule' is lateish, but not 'Jaune Desprez' for example, or 'Blush Noisette'), Banksiaes are the earliest, but otherwise I'm not sure. You might keep your eyes open as you go about and see what's flowering when, and specifically in your area.

Thank you, this is very helpful and interesting! I am noticing specifically that the wichuranas are divided into two distinct groups - early (finishing bloom now) is American Pillar, Thelma, Dr. Huey, and the large flowered climbers (New Dawn, Awakening, Blushing Lucy). Late (starting bloom now) is Ethel, Dorothy Perkins, Lady Godiva, Paul Transon. Are there any obvious genetics behind this? It seems like an equal mix of the one-time bloomers and the repeaters. I love it - it really extends the bloom season!

I think that the bloom time of all roses is dependent on the local climate, adjusted by the rose's DNA. In my zone 9/10 Mediterranean climate, the banksias (usually) start blooming in January, followed quickly by some of the tea roses and tea noisettes in Jan or Feb. The hybrid giganticas Fortune's Double Yellow and Belle Portugaise bloom around Feb/March. All of my roses are blooming by mid April. That is USUALLY - this year we had strong cold (for here) storms with lost of rain and wind from the end of Dec through the beginning of April, and none of the roses bloomed at all until late April after the sun came out. They were all in bloom by May. So, I think that the warmth or coldness of the local climate has way more of an influence on when the roses bloom than their DNA, but the DNA probably sets the order in which they bloom. So, I do not think you will find a database which can tell you when ramblers or any other type of rose will bloom by date, and if you do it will only be accurate for one specific geographic location.

Jackie

Thanks for all the feedback! It's helpful in sorting this out. Clearly they will bloom at different times in different climates, but there is still a consistent blooming order, and the factors that might cause them to bloom more quickly or be delayed also is quite consistent - they always fall into line and bloom in the same order.