Orchid - Diseased Leaves

What's up then? They were the peak of health when they came from McBrides. When I went away for a week I moved them to a cooler room, and put them on a west-North-west facing windowsill. These marks were there when I came back (unless I didn't notice them before I went)

Prior, and since, I have been moving them to kitchen windowsill - kitchen is somewhat too warm for them; window faces East-South-East - and then back to, cooler, corridor for the night.

Closest match, in my Orchid book, suggests too much sun / sun burn, but although my photos look quite like that when I put the book next to the plant they didn't look the same.

 

We are talking Cyms aren't we?
Are these leaves on psuedobulbs that have already flowered? Could just be natural dieback.

 

Yup, sorry I should have said.

Seems like quite a lot of dieback though - its on quite a lot of leaves, but not all plants - and the things were a picture of health when they arrive from McBean's :(

I've had a thought. Been thinking HOW it could be sunburn if they have, also and for longer, been sitting on kitchen windowsill. Every night they are moved from kitchen to corridor, and presumably when I put them back in kitchen next day they are not exactly aligned to window / sun at same angle as day before. Whereas, when on West window (even that that faces a bit North of West, and kitchen faces a bit South of East) they were left like that for a week - so in exactly same orientation to sun, each day.

 

They're monocarpic. One year they start, one year to grow and bloom, third year to start dying.

 

Ah OK, could be as simple as that, and that would explain them looking like they are getting really sick - rather than just a bit of sunburn. Cymb's are new to me ...

There are good strong shoots coming, for the new pseudo-bulb formation, so I guess I will just wait and see what happens. I'll also dig out my proper Orchid book and see if it has an explanation, and photos, that puts my mind at ease - have only looked in Dr Hessayon so far, and he's quite brief and to-the-point on such things as you will know

 

Certainly sounds like it.

 

Although ... no sign of a flower shoot cut off from the pseudobulbs that have leaves going brown.

I think I should send the photos to the supplier to ask their advice