Oncidium Wildcat 'Rainbow' help!
 

Hey there, a couple days ago I found this orchid at my local box store. It caught my eye as it was a single Oncidium amongst a crowd of Phalaenopsis.

I did buy it in bloom and it currently still is, but at the end of this spike's cycle, with some flower 'deterioration'.


There's an album of some of the worries I have with this flower. First of all, is that the pseudobulb is shriveled and darkly spotted. This is also apparent on a new pbulb that is growing. Leaves are also dotted black - somewhat reminiscent to me of a bacterial infection (hopefully not)..

Also, this orchid is potted in Sphagnum moss. I wanted to wait until the bloom is done to repot it but if need be I can do it ASAP.

I'm basically looking for some diagnosis/prognosis on this orchid. Thanks!

Anyone?

There are a handful of Oncidium crosses and species that I know of, that can have those black spots on leaves and p-bulbs. Onc. Sharry Baby is a common cross that exhibits these spots - every Sharry Baby I've ever grown or seen has had them. The spots are harmless, and are simply a trait passed on in breeding. As long as the spots you're seeing aren't obviously sunken or raised (which is a possible sign of bacterial rot or other infection), I wouldn't worry about them.

The p-bulbs being shriveled is likely a watering issue - either the potting mix has been kept too dry (yup, even sphagnum can be kept too dry), or the roots have rotted due to over watering. All of my orchids' p-bulbs tend to be less plump after a month or so, than they were at the store or greenhouse, and that's just because my environment is drier (low humidity and fast-drying mix). I'd say lift the orchid out of its pot and take a look at the roots. If they look healthy, then it's likely just been under watered. If they're all dry and hollow, then they're no good, and you'll need to nurse your plant back to health.

In the case that the roots are bad, you can let the flowering finish (which it sounds like is already happening), or cut the inflorescence off and begin nursing your plant to health. Keep in mind that producing and maintaining flowers is energy intensive, so if the roots are bad, I'd be inclined to cut the inflorescence and start rehabilitation.

Sorry for the long winded reply; I like to be thorough and cover all the bases. I hope this eases your mind, or at least answers your questions. Happy growing!

-Tim

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Thank you very much, Tim! I've heard of the spotting being pretty common - but suppose you can never be too safe. As soon as I find a nice pot I'll cut the spike and repot it taking a look at the roots.
Thank you so much for putting my mind to ease!

No problem at all :-) Orchid growing should be a calming experience, so I'm glad I could help.
-Tim

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There is nothing to worry about your plant.
While still in bloom continue watering once a week until the flowers are all gone. The shrinking of pbulbs either due to overwatering and the roots are rotted or dehydration. Some Onc leaves have cold droplet and sun dark spots or mechanical damage from biting insects. Cut the spike when the blooms are gone and if you decide to repot because you are uncomfortable growing with moss=make sure not to disturb the roots too much. You will notice Oncs have very fine whitish roots.
Its a great help to know your grow zone, what light source your plants have and the humidity percentage of your environment.
Just follow the culture of your plant and its always wise to learn where your plant originally came from in nature.