Research and Current Profile of Iranian Production of Damask Rose
I found this document on the web about growing damask roses in Iran, where they raise these roses for rose oil and rose water. It is a BIG industry there. So I would think they would be pretty good at caring for this class of rose. Interesting that they say damasks are drought tolerant (which would make them great for Southern California). Also I found it intriguing that they describe irrigating damasks only 2 or 3 times per year! In desert conditions too. This makes me wonder if one reason why some have trouble growing damasks in hot dry regions (like Southern California) is that they water their roses too much. Could it be that damasks, which come from the Middle East, actually prefer a long dry summer dormancy? Perhaps without that dormant period they may grow extensively, but at the expense of flowering.
I've read about this in certain salvias (with nurseries saying don't water and feed too much or the plant will grow huge and gangly but won't bloom much) and in addiition I've seen a California native rose, R. minutifolia that thrives on going completely dormant in the summer (to the point of being crispy dry and dead looking). The botanic garden near me, which has huge stands of it they've had 50+ years, gives this species rose zero summer water, doesn't fertilize, or mulch it. The plant responds by looking dead as a doornail in summer. However, the moment the rains come it greens up, flowers heavily, and produces bumper crops of hips. Then I hear of rosarians who water R. minutifolia normally in summer (like their other roses, often moderns), or who live in high rainfall areas, and it dies under those circumstances.
Food for thought anyway that treating all roses alike/similarly in one's garden may not produce optimum results in all classes of roses. Maybe imitating as close as possible the conditions where a rose is native is worth considering.
Here is a link that might be useful: Research and Current Profile of Iranian Production of Damask Rose