Are these orchids dying? They are flowering but the leaves are turning yellow

Question

We moved and I followed some good advice I got here and moved them to the basement. Prior to that they sat in late summer sun for a week until we arranged everything in the house. At that time it rained heavily, followed by torrid sun, and one of them started showing the black spots that you see in the picture. The others also seem to be affected by something, it looks like the leaves are dying, yet all of them seem to be about to flower. What is wrong with them?

They are now sitting in an above the grade basement window facing south. I am located in Toronto if that helps you in any way.

Answer 1

I asked a similar question (How Should I Take Care of These Two Phalaenopsis Orchids with Different Behaviors?) a few days ago but still no answer.

I've done further more investigations about that, going to a gardening store and trying to get some help, but even those people weren't super helpful. The suggestions I received were to let the roots receive sun through the transparent pot, and a few other advices that did not make sense to me.

However, you need to check the roots. If they look somehow rotten and not fresh (like my second pot in that question), then you've over-watered them. Leave them somewhere warm with appropriate humidity, and do not water them too often. A small cup of water (ideally with a few drops of Orchid food) once a month should do.

If your roots look whitish gray, then that apparently means they're not able to receive enough water, but as you may noticed, my first pot's roots look like that, but they're having good flowers, doing well. So I'm not too worried about that.

I've moved my pots away from the window which was obviously colder than other parts of the room, and have placed them close to the radiator. Both pots seem to be doing better over there.

If you're seeing any rotten roots, you better remove them carefully, and also not try to shove in or cut the roots that are growing outwards like in your second photo.

I may also mention that I live in Ireland where our dehumidifier sucks at least 5 liters of water every night from the air, so keeping them warm is enough with the natural humidity of the atmosphere. Orchids like warm and humid conditions.

Answer 2

The near plant shows strong signs of being sunburned. Many phalaenopsis species can take higher light in natural conditions, and may even, with a few species, be found growing in nearly direct sunlight...but(!) with very good air movement, adequate moisture at the exposed roots, no previous dry plant conditions, etc. Burn spots do not recover. Yellowing at that bend in the leaf, where that bend is toward the light is a give away of that condition. If you have a way to filter that light that your plants receive, then do it, ASAP. I, too, have been there with this genus of orchid, and while I grow a couple dozens genera and more species, I grow mostly the phalenopsis hybrids that friends have given me to help them recover, plus a couple species that interest me for interesting foliage and ability to grow in the home on sticks or pieces of Oak bark cork. What I noted above about yellow at the leaf bend toward the light applies to many types of orchids, but not all. Some cymbidiums, for example, may tolerate some leaf yellowing from high light, as long as the plant is not too dry, and most of the leaf is at least light green. In fact, with some cymbidiums, leaves that are too dark green are a sign that the light is too low, and the expectation of seasonal flowering should be reduced.