Only thing that comes to my mind is because it's in a pot. It gets warmer faster, pushes growth faster, than the ground. I could definitely be wrong. But that's my thoughts. The pot take away a zone for winter, but get warmer faster in Spring.

Here’s Indigo Knights complimenting the early bloomers:

”Nice colours! I wish mine looked like yours. I hate my bluing.”

Back in the day, I had to explain to my nieces that if they wanted roses for their weddings, early May weddings wouldn't happen. Fall was a lot easier to plan for. The one who wanted earlier summer ended up carrying a mass of Noisettes (I had hoped for Eden, but it produced several dozen excellent blooms of light brown with pink edges that year.)

Roses exist with the thought of making us eat our words. The year the National Fall show was in Philadelphia (planned, in part, for best bloom time there) there were very few HTs of any color, but an entire table (I'd guess over a hundred) of the red HT Uncle Joe. And almost as many Toro roses. (Another story for another time.) That year Uncle Joe was excellent for everybody, the other HTs, not so much.

I think Alana is right, Bart.

I agree with what Sheila says about Alana's comment. Also, lots of water helps and realizing the genetics of roses differ and will affect how early they bloom, and finally, pray to the weather gods. For my garden, water is the most important issue and is the best fertilizer. Diane

So, if bart bart planted her potted rose near a wall with a Southern exposure would that have the same effect?

Jackie

Yes, it can. But, that's a double edged sword. If the rose is once-flowering, the extra heat from that hot wall can cause it to flower for a shorter time than it might have if it was planted away from the wall. It's a balancing act between light, temperature and water. Too little of any of them will prevent the desired result...flowering. Too much of any of them will have the same effect. If the rose repeats, you can bring it on earlier and faster, but with a shorter flower life for each flush, by putting the plant in a hotter position. If it's once-flowering, you can start flowering earlier, and stop it earlier, by increasing the heat. The reason many once-flowering types flower so long and often appear to "repeat" in coastal climates is simply due to the heat and cool patterns. In Pacific Palisades, Banksiae flowered from February through August (when the heat started). O'Neal blueberries flowered and fruited nearly the same period of time. Many once-flowering roses kept blooming as long as it stayed "spring-like" weather. The same plants, grown inland where the temps were thirty to fifty degrees hotter, stopped flowering as soon as the heat hit. Right here in north Santa Barbara County where it's been COLD for months, with one or two short ventures in to "heat" (mid seventies) then drops back into the 60's, Banksiaes, Fortuniana, Basye's 86-3 (Laevigata X Banksiae), Xanthina, Primula, Hugonis, all once-flowering, have flowered, stopped, begun flowering again and continue flowering because the temperature changes have tricked them into "thinking" spring has come, gone and now returned. If I grew them against a southern wall where the solar heat kept the wall "hot", that flowering could easily stop for the same reason it stops where it's hotter. I'm sure you've noticed your once flowering types often flower longer than they do in hotter areas.

You people are the best. Now I'm going to start mulling over how/if I could place this plant out in the garden to get it to bloom earlier. Darn it, yet another reason to wish for a little cottage out there!