Can anyone identify what might be causing this leaf to have black steaks on it..?? None of the other leaves on this plant have these steaks and at very healthy, large, firm and dark green.
Hi!
Looking at this weird leaf, I would surely do one thing, isolate that plant. Hopefully we are not looking at the early stages of a fungal attack, which could spread easily to your other plants as well.
Here is a link to all sorts of common Orchid ailments. https://www.staugorchidsociety...
I'll use copper and hydrogen peroxide. The other solutions are $75+ which is out of range for the value of my orchid collection and not very natural. 🤷♀️
Hmm, I have totally no advise/pro or con on those, I have never used either.
My method is usually - isolate immediately and throw it out if no improvement. But I am a bit leery with the Copper....
It surely looks like a fungal infection. I guess I'll try the copper and peroxide and see how they work. I used copper very successfully on my roses and in my aquarium. I've never had issues with orchids before this. And have grown them for decades. It's isolated and I'll treat it's table mates, too. I've only had it 6 weeks. So, I think those on that table should all be treated, just to be safe. Time will tell 🙏🏻
!
Decades of Orchid growing? You must have beauties! 
