I’ve been growing miniature cymbidium orchids (in spite of their name, they’re fairly large plants) for a number of years and one thing I’ve learned about them is that they like a distinct cold treatment in the fall. They can even take light frosts and, in fact, a bit of frost seems to do them good.
I’ve learned to put mine outdoors for the summer in full sun (you’d need partial shade in hot summer areas) and to leave them there until late fall. In fact, they don’t seem to even mind a light covering of snow as long as it melts away rapidly.
In a milder climate than mine, you could leave them outdoors all winter, bringing them indoors only on really cold nights, but where I live, prolonged periods of freezing temperatures make that impossible (they are subtropical plants after all), so I bring mine in for the winter when temperatures begin to drop to near freezing not just overnight, but for days at a time, usually well into November.
Indoors, I put my cymbidiums in a bright cool spot and water modestly until they bloom, usually in winter or late spring. In spring, I repot and/or divide if necessary (when their growing medium decomposes, therefore every few years), increase their watering and begin fertilizing. They go outdoors early, as soon as there is no frost in the air, and again spend summer and fall outdoors.
I find them to be among the easiest orchids to grow… as long as you have the possibility of putting them outdoors for the summer and don’t bring them indoors too early.
Don’t try this with most other orchids. The vast majority of those grown as houseplants, including the ever popular Phalaenopsis, are tropical plants and need at least moderate warmth at all times. They should definitely be indoors by now in all but the warmest climates.
Sigh. My cymbids just keep getting smaller. What is your growing medium?
They’re considered semi-terrestrial, so I mix about 2/3 of a standard, bark-based orchid mix with a peat-based houseplant potting soil.