My father impulse bought this Rossioglossum grande at our local market without letting me know. I looked up the care requirement for this orchid and it seems like it is a cloud forest type orchid, which moisture level is something I dont think I can provide.
Anyone have advice on how to care for these type of orchids in dry hot climate like zone 10b?
Grow on the shady side (bright shade) and keep moist - like most Oncidinae, small bark in plastic pot works fine. Doesn't like to dry out. Our days are warm, but our nights cool off more than in most places. And that's enough to keep most cooler-growing orchids happy.
Rossioglossum Grande comes from +/- 8600ft in Guatemala in temperatures around early/mid 20c right down to single figures. I would think that so long as you water profusely during the summer then hold off with much less water in winter you should be fine because the compost itself will regulate the plant hydration.