nope, you do not need cool temps for flowers

[Ray]

Several years ago I tracked min and max temperatures.

Of the 365 days logged, 222 had diurnal ranges of 15degrees or more, occurring in every month. It was not until late October, however, that the 14-day running average was reduced by that much, and sure enough to, spiking started about 6 weeks later.

[jldriessnack]

Mine flower all the time, any time.

[Clawhammer]

The temperature on my windowsill changes throughout the year, especially at night.

[Dorchid]

Originally Posted by Clawhammer

The temperature on my windowsill changes throughout the year, especially at night.

This

[jldriessnack]

So then, if my phal flowers in the summer when nights are over 70 for me and day is just below 85, and in winter when everything is 10 degrees cooler, how would you explain that?

[Clawhammer]

Originally Posted by jldriessnack

So then, if my phal flowers in the summer when nights are over 70 for me and day is just below 85, and in winter when everything is 10 degrees cooler, how would you explain that?

Genetics. Some species flower in the spring/summer, some in the fall/winter

It is undeniable that a temp drop will trigger a bloom spike in most if not all phals. Growers do this en masse to prepare inventory for retail sale. It open common practice.

Is temp drop necessary in most windowsill conditions? Probably not for most complex hybrids.

These two concepts are not mutually exclusive.

[WaterWitchin]

Originally Posted by jldriessnack

So then, if my phal flowers in the summer when nights are over 70 for me and day is just below 85, and in winter when everything is 10 degrees cooler, how would you explain that?

Ummmm... A temperature drop?

Maybe I qualify for your very first explanation, where you qualify it's only about windowsill growing. I've done that, and do that with some phals. But then you try to compare your theory to everything from Asia to Borneo, which I presume means species. Which aren't hybrids.

If we compare a phal to a phal, regardless of species or hybrid, in windowsill growing most likely they will bloom somewhere along the line. Unless the temperature stays too high year 'round, or there's no diurnal curve. In a windowsill grower, there is likely a temperature change and a diurnal change as well over a year's growth.

Regardless, unless it's a species with more specific requirements, phals are tough and bloom regularly regardless of a ten to fifteen degree click of the thermometer. Because it's happening. It's why hybrids are the go-to for the common marketplace. It makes live easier for those who just want a phal around they can play with and successfully bloom.

For a beginner, who comes here and says their phal isn't blooming, the first suggestion is a 10-15F drop between day and night. Because it works. That's what commercial growers do to have tons of hybrid phals available at a certain time, regardless of the occasion.

Other than saying you think a requirement of a drop in temperature isn't necessary, in your culture and environment, making a broad statement that it doesn't matter, period, is more than a stretch. You can expound away... but I think your theory is flawed for many reasons.

Spoken by a grower, not a moderator.

[estación seca]

It occurred to me that there are Phals and there are Phals. The summer flowering species like bellina and violacea, and their hybrids, aren't the ones manipulated to flower with temperature drops. It's the winter and spring flowering species like amabilis, aphdrodite and schilleriana, and hybrids, that are manipulated to flower with temperature drops.

[Mr.Fakename]

Temperatures alone are just a piece of the puzzle.

Light intensity and exposure time, fertiliser, water abundance or stress, humidity and so on, are all parts of the same variable.

WW summed it up by saying your theory is flawed.
You mix species and hybrids, day/night variations with seasonal variations, want people to provide detailed scientific explanations to back up everything they say but don't show proof of what you pretend.

Just one example of the things you broadly state :
"First off, in most of southeast Asia where these orchids grow, no such cold spells of 55-65F occur. In Borneo, night time temperatures are often over 75F, and in Malaysia the average temperature is usually above 75F as well - these are tropical, hot rainforest climates."

Phalaenopsis are distributed from China (eg. Phalaenopsis wilsonii) up to Northern Australia (eg. Phalaenopsis amabilis).
Just a portion of Phal species are found in Borneo/Malaysia.

And even for those located in Borneo and Malaysia, you missed a somehow important thing about geography: mountains.
Phal amboinensis and Phal venosa both come from Sulawesi.
Except that amboinensis is found at sea level where it gets the "night time temperatures are often over 75F"; and venosa is found up to 1000m altitude, where it gets the "cold spells of 55-65F".


Whatever your opinion is, you don't have to be cocky about it and systematically diss other posters.

[Ray]

There are “genetics”, “triggers” and “available resources” to consider, and they may work together or apart, and as Clawhammer stated, are not mutually exclusive.