John M
Orchid Addict
Yes, they do need hot summers. They emerge from the earth late in the spring (June, here); but, the frost is out of the ground for over 2 months by then. They have to grow very fast to reach 5 or 6 feet and get their flowers open, before things cool down again. If the summer is not hot, they don't grow fast enough to mature and actually bloom. When that happens, it's very disappointing to see a plant loaded with buds; but, you don't get to see any of them open up before the plant begins it's autumn dieback.