Black Rings on Dendrobium-Phalaenopsis Hybrid

[KristenJ]

Thank you!!! Can you grow all of my orchids? Lol. I will get to work fixing all of these issues! It's my fault really, he is the second orchid I purchased. I bought him and a Nobile Dendrobium at the same time and I had no clue what I was doing, or what I was getting myself into. The seller told me he was a Dendrobium Phalaenopsis Hybrid "Blue Boy". But she told me to give it the care requirements for Cattleya. As always, I continue to learn more and more. Thanks again!

[King_of_orchid_growing:)]

Both the Den phalaenopsis hybrid and the Den nobile hybrid have similar lighting needs to each other, which would be moderately bright indirect to bright indirect light.

It is also preferable to provide the Den nobile hybrid with a winter rest as well.

Hope you're able to fix your problems.

[KristenJ]

Thanks again for all of your help. The latest leaf yellowed with no black rings. I'm treating for fungus and repotting too. Thanks again!

[NYCorchidman]

Your hybrid does not take winter rest. It can acutally die from being exposed to cold, so please don't!

Depending how much of what is in the background, it may withstand slight cooling, but it is not necessary.
It is best to grow warm year round. With this care, you will see it bloom more than once a year.

If you can't keep it warm enough during the winter, do your best to provide as much as warmth as possible. Water less but not bone dry.
Keep the canes fat, not wrinkly.

With regard to light, this type of dendrobiums take much less light than nobiles.
They can be grown under the same light with great results, but nobiles benefit from much more light than these.

I grow my nobiles in the direct sun, but this type of dendrobiums will be burned to death in the same condition.

About the rings, there has been a few posts in the past and mine was one of them.
No one had answers and I don't either.

I too believe it's either virus or fungal.

Unfortunately, my dendrobiums with this this kind of symptoms did not do well and I tossed them.
Now when I see something like that, I toss.

Physan 20 will not help.
I find physan 20 almost uselss actually.

It maybe be good for certain things like surface sanitation and such, but personally find it uselss as it does not help with diseases, not even the most common leaf spotting!