Agree, sunburn. I would bring them into the house and not remove any leaves until they dry up and fall off. Some portions may survive. You will need to water less because there are fewer living leaves. Plants that survive will soon make new leaves. It will take 2-3 years for survivors to flower again.
__________________ May the bridges I've burned light my way.
I got my own basket of fried orchids from the heat of this summer sun. Phals seem to be temperamental about coming back after such damage. I wouldn’t rush your orchids to low light suddenly because that could cause the opposite problem. If they suddenly get less light and get the same amount of water, they might start rotting. My dendrobium did this recently. I know they’re not the same kind but I think it makes sense anyway. Also the sunburn mine got looks ugly but the infection did not spread.
Phals. are low light plants. One thousand foot candles is ideal. That is bright shade with no direct sun. I would absolutely move them from excessive light right now.
__________________ May the bridges I've burned light my way.
And about the Oncidiums. Oncidiums are a broad group but generally are much more sun tolerant so it’s no surprise they were not sun-affected. My neighbour grows her’s in full sun - some suffer, some flourish.
And about the Oncidiums. Oncidiums are a broad group but generally are much more sun tolerant so it’s no surprise they were not sun-affected. My neighbour grows her’s in full sun - some suffer, some flourish.
Ah, maybe my oncidiums aren’t doing well because they need more light. That’s an idea I didn’t think of.