I tried growing cumin last summer in the Four Corners region of Colorado, hot days, cool, nights, short season. Interesting result, the darn plants went to seed WAY too early to get a good crop, less than 60 days, and only a few seeds per plant. I think they were very stressed plants, and I wasn't about to determine what the stressor was. But, it figures that cumin CAN produce in well under its packet listed season length, and that idea production should follow from syncing up its season length with your own, I would speculate that you and your cumin can form a relationship to produce seeds over a few years of breeding and experimenting. I intend to experiment further with cumin myself.