Is it disease or sunburn?

[Ingrid76]

I recently returned from an out of town trip and found my dend (Dendrobium Blue Violetta x Red Maroon #693) orchid with yellowing leaves. My first reaction was sunburn, now I’m thinking it might be something else. It looks like its spreading. Any suggestions?

[King_of_orchid_growing:)]

First signs of root damage?

I know that my Pleuros did the same thing, (yellowing from the tip of the leaves) , when that happened.

When Disas get root damage, the same thing happens. The leaf tips are always the first to die.

If so, it might either be:

a. overpotted
b. over watered
c. over fertilized
d. roots are not getting enough air (must improve drainage in potting media)

Other than that, I can't think of a reason why your leaves would yellow from the tips like that. Sunburn is patchy.

[Chantelle]

hey King,

This may seem silly but what does it mean if its overpotted?

[Ray]

Overpotted = in too large of a pot for the root system.

[Jbyron]

That whole "over pot" idea always bothered me. It seems to me that the issue with the pot being too big is that the it does not dry out evenly and the interior portion stays wet while the outside and surface, if its a clay pot, dries.

Of course, in the wild orchids have no pots at all so roots dry as they do with a mounted orchid. The problem with mounted orchids is the daily need for watering, so we resorted to pots. The idea of any kind of pot is probably our biggest cause of dead orchids.

So it seems the "over pot" issue is really just over watering again.