Sounds like its just taking a rest. I do know that cool nights, around 55F for a couple weeks is how the pros' get them to bloom out of season, so if you can, you might try that. Just an afterthought, when they 'were' blooming, did you remove the old flower spike, or did you cut it back and allow it to bloom again on the same spike? Sometimes when you do that, it takes a lot out of the plant, and it needs some time to recoup. Hope this helps.

Have you tried a little Superthrive? My plants sure like it~~

Did it bloom in winter before? Could be a spring/summer bloomer? If it hasn't bloomed for a few years, something is off and the plant isn't happy. Try increasing the light. Some Phals want more light. I wouldn't fertilize with anything unless you want more green growth.

Jane

Phals sometimes go into a kind of slump for no particular reason. Shock therapy may work; dump a little light ice from the freezer on it. Not enough to freeze it but just enough to wake it up a bit...

Looking at your post again, the most plausible explanation for your problem is your geographical location. Minnesota is is not the best place in the world to be growing tropicl orchids. The main problem will be not be low temps or humidity, which I assume you take care of, but the lack of winter light. In January your plants will be receiving less than 20% of what they could expect in their tropical homeland. My advice therefore to anyone growing tropical orchids in northerly latitudes is: during the winter months REMOVE ALL SHADING. Let the plants sit in full sun from dawn till dusk until the sun reaches 45 deg at noon ( half way bewteen the horizon and zenith) then VERY GRADUALLY start to shade again. Good luck. PS If this doesn't work try the ice IN SUMMER.