Sheath covering PseudoBulb Darkens

[FrankP999]

I am new to catts having grown mostly phals for years. I have a healthy catt that is turning black on the sheath covering the pseudobulb. Is this part of the process of the sheath drying and turning into the paper-like covering seen on older pseudobulbs? The sheath was green color and now is blackish but not a solid black. Thanks

Frank

[tucker85]

Two points, first the covering of the psuedobulb does die off leaving the papery brown material that covers old psuedobulbs. That's completely normal growth. Second, That same covering can create an ideal environment for fungus or insects. Occasionally fungus will get in there and spread to the rest of the psuedobulb. I have lots of catts and this only happens once in a while. I remove that material over the psuedobulb as soon as it's weak enough to peel off without harming the orchid. The most vulnerable area is right at the top so even just peeling back the top, once it turns brown, will keep water from collecting in there and causing problems.

[RosieC]

I only have very limited experinece with catts but I would expect it to go brown/white and papery, not black. I would guess you have some kind of fungas as tucker has described.

[FrankP999]

Thanks. I sprayed the area with Physan to be safe.

Frank

[mojomick]

As soon as the sheaths turn begin to turn brown and dry I remove them. I think it is a good habit to do so.