HELP PLZ!! DISEASED-SICK PHALS =(

[camille1585]

The fact that it's mostly phals and that your temps did drop to as low as 49 could still indicate cold damage. Phals really don't like cold weather, and it doesn't need to be below freezing for chill damage to occur. They can show cold damage at 50 and below, especially if there is highish humidity. The symptoms pretty much match it. Also, while the cold may not damage the plant in itself, it can also weaken the plant to the point where it is extremely susceptible to disease.

[Jkelee]

So I should CUT off everything YELLOW??
Even if that's EVERY last leaf?

[prmorganj]

Well the problem is that the plant can not make food where the 'green' is gone in the leaf. You are supporting the dead 'yellow' leafs from the main stalk. Orchids can recover with time even when those leafs are gone. If the leaf is yellow it is not contributing to the life of the plant. It is only sucking the life out of it. I believe your only chance is to remove any leaf that is fully yellow and keep the plan moist (not wet) and in as much humidity as possible. Its happened to me and I still have those plants. Good luck. I yield to anywone else with a better idea.

[harrywitmore]

One thing to remember. Temperatures can vary greatly within an enclosure. Were the Phals all in one spot?

My large greenhouse is heated and while the thermometer showed it never got below 45F at the coldest spot and most not below 55F, I'm seeing plants with freeze damage. So, in pockets it actually got below freezing. I would have never guess this would happen but it did.

[Jkelee]

Yes, the Phals were all in the same spot. not all were damaged, but 75% of them.

[phearamedusa]

Here's another possibility, while the temps may have stayed above 49 with the heaters running. Was the chid house insulated in any way if not, you could have got condensation forming above where these plants were, that then dripped onto the Phals below. I don't know what kind of humidity you have in your chid house, but even a moderate humidity in the day time could translate to high humidity as the temps dropped. The condensation that hit the Phals would be very cold and would cause those larger roundish dark spots. I've had something like this happen to some of my orchids, damage will vary depending on where the condensation forms and drips, so you have some that are fine(no damage) and others that are damaged to varying degrees. Good luck with this, I know how attached we can get to our chids, and this is just heart breaking.

[King_of_orchid_growing:)]

It's cold damage like many have said. 49 F is too low for Phals. 55 F is the absolute lowest any one can go with Phals. 60 F is a safer low end temperature.

Not sure about your plants' survivability. Some may make it others may not. They don't all appear to be in the same state of damage.