Phal Temperature Resistance

[labyrinth1959]

I am wondering what is the lowest temperature Phals can easily handle for an extended period.

A second related question is how to stimulate a Phal to produce a blooming spike.

[Orchid Whisperer]

The usual recommendation is 55 F to 60 F.

Ask me for a recommendation, I would say no prolonged exposure lower than 60 F especially if the plants are getting wet (rain or other water).

Ask me what I have personally done, I would say I have pushed to lower temperatures than that, sometimes successfully, sometimes not.

What is required for blooming is an overall temperature drop of 10 to 15 F for a few weeks. If your plants are experiencing summer outdoor temperatures in the shade, fall temperatures should give you enough of a temperature drop to bloom, if the plant is otherwise healthy enough to bloom.

[estación seca]

Even one night at too low a temperature can stop them from growing for many months.

[Orchid Whisperer]

e.s., I am not discounting your experiences, but I have had (unintentional) exposures below 40 F, most plants unaffected, no obvious change in growth. I would not recommend temps this low.

[estación seca]

It may also have to do with ancestry. Some Phal species are from very warm and humid areas, others less so.

[Orchid Whisperer]

I agree ancestry is important. My "panda" or "harlequin" Phalaenopsis (Phalaenopsis 'Elegant Polka Dots') is very intolerant of cold. I've learned to bring it in before temps hit 60 F at night.

[bil]

In the winter mine are routinely at 12C

[Subrosa]

I like having plants outside as much as possible, so I break my plants down into groups based upon the minimum temps I want the plant to experience. I use 10 degree F increments and treat Phals as 50F plants. As long as night time lows are reliably over 50F they're outside. I did have a couple hybrid Phals in a room that saw temps in the low to mid 40s F with no damage. The plants did stall a bit however.