This happened within at most two days

[HumbCa]

Hello,
I have a worrying problem, hopefully you can shed some light on how to respond to it.
I Hadn't checked my orchids for two days, I just went in to check on them and water them and saw this:


Some additional data: We've been hit with som unusually low temperatures lately, especially at around 03:00 AM, it can get to below freezing point, maybe this is somehow related.
Thanks for your help

[estación seca]

That might be cold damage. Are you in the mountains?

[Keysguy]

Definitely looks like it got chilled. You may very well lose that one. Those big thick Cattleya leaves are just loaded with water and they do NOT like cold weather.

Where are you in Italy that it got that cold in the middle of summer? Up north in the mountains?

[HumbCa]

Indeed, I am close to the mountains. That's not a Cattleya, that is an Epidendrum Nocturnum, what can I do?

[SouthPark]

Originally Posted by HumbCa

Some additional data: We've been hit with som unusually low temperatures lately, especially at around 03:00 AM, it can get to below freezing point, maybe this is somehow related.

That will likely be the cause of it. If temperature go out of the recommended growing range for these kinds of orchids, or if the temperature changes from one temperature to a significantly different temperature at too high a rate, then that can cause cell issues too ----- leading to the bruising effects or cell collapsing effects.

Some orchids getting the water frozen during shipping in snow countries (or even getting too cold in cargo hold of some aircraft) can even have their pseudobulbs go all mushy ----- usually unrecoverable situation.

Hopefully your orchids can recover! If the temperatures get too cold etc, then definitely bring them inside.

[estación seca]

First, try to keep it warmer. Don't water. Dry plants tolerate cold better than watered plants.

When I have frost or or heat damage I don't cut the leaves. The damage may be worse or less than you think. I wait at least a week to see the full damage, and then cut the leaves.

Edit: I agree that is not Epidendrum nocturnum, which is a reed-stem Epidendrum. It is a Cattleya species or Cattleya alliance hybrid.

[DirtyCoconuts]

Originally Posted by HumbCa

Indeed, I am close to the mountains. That's not a Cattleya, that is an Epidendrum Nocturnum, what can I do?

Are you sure?

The one that is native to Florida?

I have several of this plant and it looks nothing like the plant you have posted.

I am sure it is some distinction but it is confusing

[Ray]

It’s definitely a cattleya-type.

[SouthPark]

Originally Posted by HumbCa

Indeed, I am close to the mountains. That's not a Cattleya, that is an Epidendrum Nocturnum, what can I do?

Maybe those plants down toward the back - in the background - are Epidendrum Nocturnum.

The plants showing the bruising/black-coloured patches in the large pots in the foreground are definitely cattleya type. Did any of the other types of orchid in the green-house get this same bruising condition?

[aliceinwl]

If you can do it, maybe try bringing them in the house or somewhere heated at night? When I’ve had plants get this degree of cold damage, unless I find a way to keep them significantly warmer, they end up succumbing.