Cold Treatment - Phals - when to warm?

[MisterGuy]

I couldn't figure out how to phrase this question well enough to search for an answer. I'm in a new housing situation, and this year, my phals spent the summer on my back porch in bright shade by hardwoods and pines with a southern exposure. Our temperatures started bouncing around, so I moved the collection inside, except for a few of the phals, because I wanted to let them cold treat for a few weeks. When I was growing them entirely inside, I kept them on heating mats that went on and off with the lights while they were spiking, so "cool" was only 67-70 degrees but warm was in the 90s.

Now, outside is getting really chilly and is only getting to the 70s some days. The first of the outdoor plants has a tiny mitten forming that I'm confident will be a flower spike. As soon as I see that, I can bring it in right? I can't mess up the hormones by warming it once the spike exists, right? I want to keep it in brighter, warmer conditions to get it growing faster asap, to try and spread the flowering season among my phals as far as possible.

[Paphluvr]

If the high is only getting to the 70's some days they should be in already. These would be considered chilly temps for Phals.

[MisterGuy]

Originally Posted by Paphluvr

If the high is only getting to the 70's some days they should be in already. These would be considered chilly temps for Phals.

Thanks! By Southern Boy standards, it's freezing. In reality, it's hit the 80s except for a few stormy days. I'll go ahead and bring them in this week, I just didn't like doing it until they were committed to spiking. I've found, personally, for orchids, they're less temperamental than I am, having grown up in the Carolina sandhills.

[Ray]

For reliable spike initiation, after growth under warm conditions, the plants need to experience 10-14 days of an average temperature that’s 10-15 degrees cooler, then warmed up again.

[MisterGuy]

Originally Posted by Ray

For reliable spike initiation, after growth under warm conditions, the plants need to experience 10-14 days of an average temperature that’s 10-15 degrees cooler, then warmed up again.

Thanks,

I definitely remembered that as them needing a 10 degree difference in days and nights, and didn't realize it was an average temperature thing. That's probably why several of ones I brought inside are blooming just as fast as the ones I left on the porch.

[Ray]

Pretty much any reduction CAN initiate spikes, but for commercial growers who rely on them, it's the 10°-15° AVERAGE that's important for reliable spiking. A 10° nighttime drop only gets you halfway there.

[Roberta]

In my condo days when I was just starting out and had a bunch of Phals, they lived in the spare bedroom and the only temperature drop they got was what happened naturally before turned on the heater (65 deg F night, 68 deg F day) The plants were a bit warmer by day because of the the lights that I found necessary to give them the light duration that they needed to bloom. I got reliable blooming... the commercial growers need a lot more certainty, so they carefully time the temperature drop to time the blooming (the orchid that blooms just before Christmas or Mother's day is worth a lot more than the one that blooms two weeks after) As a hobbyist, most of us don't really care precisely when they bloom, as long as they do it. Bring them in, they have had plenty of chill.