Canada huh? Almost certainly it's lack of light, especially at this time of year.Try giving them a couple of hours of direct sun per day. Most of mine get a couple of hours direct sun per day here in Brazil, morning or evening. All bloom. I rarely burn any. - Ian.

Since it's cold outside, the house temp is controlled rigidly. If the plant is in a steady 70F or whatever without variation, that may be the reason. 10f to 15F day/night difference is desired by them.

Nick

I agree with Ifraser...increase the light!

Jane

Definately the night temp drop, if the leaves are a dark green then increased lighting may help also.

If cracking a window at night isn't an option, maybe move them to a colder room in the evenings and back out in the mornings.

Tell her good luck,

Bob

If your plants are in a room with a bright window, try just closing the door and vents at night to keep some of the warmer air out. The daytime sun will give them a temperature increase and the nighttime fall should be enough without freezing them.

Also, make sure the shade isn't down or closed on the window, full sun won't hurt them where you are.

The ones I grew years ago were grown in a shaded greenhouse. The only variable was the temps. Flowering was consistent.

A shaded greenhouse can not be compared to a shaded location within a house. The light coming though a window is not near the intensity of what you experience in a structure where light comes from all directions.

I've done some measurements with a light meter and found if there isn't any direct sunshine coming through a window, you're probably talking 300 or so foot candles - maybe less - and that's a few inches from the grass. The more you move away from the window, the more the light intensity drops off.

That is not nearly enough light to bloom a phal.

Kevin

I have a similar problem but I am here in Arizona. Light is not an issue with mine, but I cannot get the ones I have to rebloom. They go out on the patio when the weather's not too cold, and I bring them in at night. Suggestions?

There is some info. in this FAQ that might assist.

Here is a link that might be useful: Phal blooming FAQ