I've heard of people growing Vandas outside in the San Francisco Bay Area year round. Is this possible? If so, which ones. I would assume that the vandas would have to have V. coerulea in it's ancestory. Any info woud be greaty appreciated. Thanks!
The "blue" vandas like coerulea would be the bast to try BUT be careful that any of the parents don't carry sanderiana in it. There are usually plenty of coerulea line bred hybrids around, I would study the parentage of the plants available and choose them.
Ascocenda Princess Mikasa or most Ascdas will grow cooler than straight Vandas BUT BUT will not tolerate frosts or temps in below 10c or 50 F for long periods of time. Cold winds will damage them badly also.
V. coerulea is one of the most cold tolerate Vandas around but again the rule above applies. If the weather is bad, take the plant inside at night and back out in the day provided its suitable. The flower quantity and quality will suffer but you should get flowers.