I was just talking to a coworker this morning who burns his pine needles & then tills the ashes into the soil. He swears by it for his tomatoes, but I have no idea about how it would affect roses.

Ashes are highly alkaline and high in the metallic nutrients such as calcium and potassium. The particular content varies greatly from one batch to another. Generally ashes are such a potent amendment that they pose a danger of messing up soil for a long time if overused routinely. It is relatively safer using them on sandy acid soil.

It seems a waste to burn pine needles. Wouldn't a neighbor like to have them for mulch?

Yeah, I kinda freaked out when he said that, especially since we have a "Critical" fire hazard message from the national weather service for today. Granted, he burned over the weekend, but still.....we're normally wet, mushy, and cold this time of year. We've been hot & arid. Very odd. And not conducive at all to burning things.

Then again, there are folks here locally that will burn whatever they can, since they are still allowed. In my municipality, all burning was banned several years ago.

Better to keep ashes out of your rose beds.

I would use them as mulch. If you have too much, what about a Craig's List or Freecycle posting: "Free Pine Straw Mulch!"