Problems with formosae dendrobiums - yellowing leaf tips

[catwalker808]

Calvin. I would also have said lower leaf drop of old leaves IS normal for Frosty Dawns when the temp turns cold. That is, until looking at the photos of your leaves half green and half brown. And we had much more info here.

Remember, they invented Frosty Dawn and so many other formosum hybrids. And they have grown thousands of them. We had the advantage of seeing your photos here to make the diagnosis.