Black spots on Zygo leaves and yellowing on a NOID
Hi, I introduced myself earlier in the intro thread and said I would be coming here with a question about my mom’s Zygo. Syd Monkhouse. Here are the pictures of it. What are the black spots and how do I get rid of them? Thank you for any help.
I also have a NOID that I believe is an Oncidium. It's leaves are turning yellow with brown spots.