The leaf tips of my Onc.Sharry Baby are turning brown.
I read somewhere thats for lack of enough fertilizer. I do the weakly, weekly regimen. Do Oncidiums need more?
Jungeoma
I always heard that the leaf tips turning brown was due to salt build up from the fertilizer. The common advice seems to be to flush the pot every fourth week by putting it under the tap and letting the water run through for a few minutes.
Another reason that they can turn brown is due to low humidity. Welcome to the forum!
If you are also seeing dark specks in the leaves, it is definitely due to excessive salts.
The only obvious leaf-tip symptom of under-application of a nutrient that I am aware of is calcium, and that is the blackening and death of new growth tips, not older leaves.
I remember reading on the forum cultural tips from Leo Schordje who states that leaf tips turn brown/black from lack of water. The article is referring to Phrags. but maybe it applies to other orchids as well?
I think I figured out what might be the cause of tip browning. It could be shipping and new environment stress. The new leaves don't have that and there is even an itty bitty little spike coming. I am so exited.