Indoor Phal culture. Trouble with night temps.
 

Hi, I have Phals growing in a spare bedroom. I use a space heater or I open windows to get a 80 degree daytime temp. My problem is how do I get my nightime temps lower. I know it won't be a problem in the winter but, here in the midwest the night temps have been hovering in the mid 70's. I use the A.C. and open the door and vent at night so I usually end up with a night low of 74. Any colder and we freeze at night. Is that enough of a temp change. I have read that they like a night low at 60 to 65.

About 70 F is fine for a summer night time low temperature.

Also I'm sure that other times of year besides the height of summer are cooler.

You don't want to freeze in the winter any more than you do in the summer, but that spare bedroom could be un-heated during the day and on low overnight, maybe? Many phals bloom in the spring anyway. Variation around the year is not a bad thing.

I live in the Midwest as well and have not found there to be a temperature issue. In fact, once my phals are out of bloom they go outside to enjoy the humidity, warmth and natural diurnal temp variations. During the winter, they sit in a window sill with the storm windows shut, though granted I live in an old house and the windows are a bit drafty. I have never had a problem getting them to rebloom for me personally using this method. Hope that helps a bit. Out of curiosity, do you know your relative humidity where you live? That would be my only concern.

They really only need a temp variation for about two weeks to initiate bloom spikes. Don't worry about the temps through the summer, and when fall approaches, open the window a crack at night so that you go from the 70's to the mid to lower 60's for about two to three weeks and you will be rewarded with spikes.

Phal grower,

I live in Central Florida where the night time temps in Summer rarely get into the temp range you reference and my Phals have had no issues.

I think you may have misunderstood something you read. Phals initiate their spikes in the Fall to bloom the following Spring. In order for them to do that they need around a 15 degree difference between the day time temps and the night time temps.

This can be achieved simply by putting them outside in a shady area after they bloom and bring them back indoors before the temps get to low.

Hope this help.