Small brown spots on leaves and pseudobulbs

[Sébastien Rivest]

Hi everyone,

Three of my orchids have small brown spots on the back of there leaves. For the Paphinia and the Coryanthes (first and second pictures respectively), the spots are very small and located at the bases of the leaves and also on the pseudobulbs for the Paphinia. For the maxillaria, the spots are located more at the tips of the leaves. I have tried to find what cause those spots but I have no clue. I would be happy if someone could give me a hint of what kind problem it is.

Thanks for your help.

[estación seca]

Welcome to the Orchid Board!

I think this kind of spot is common on soft-leaved plants preferring high humidity, when grown in lower humidity. I don't think it will hurt them.

[Sébastien Rivest]

Thank you for your help!

Can those spots happen due to a short period of low humidity? Because the humidity where my orchids are is generally around 75-80%, but it sometimes drop to less than 50% for short periods of times.

[estación seca]

I'm not sure. I think low humidity might be the cause.