I'd love advice for the orchid I've had the longest (1 year 3 months). It had been through some root rot which I caught 2 weeks ago - the new growth was white and turning into brown and black. I pulled out the infected 'hearts' as I was advised, and dusted w/ sulfur powder. I clipped all mushy roots I could find, and let it sit and dry for a day. Then I brought it to the nursery where I bought it - they helped me to make sure there weren't any more rotten roots, soaked it in Banrot, prepared a special mix of media that includes fine bark, shredded New Zealand Sphagnum, small pumice, and small alifor.
After this treatment the leaves look the deepest green I have ever seen them...except for these weird brownish-tan blotches that keep occurring. I cut a couple of them off earlier, thinking maybe they were due to shock, but more and more keep happening. I haven't seen any new growth that looks good. I have found some more small black/brown small leaves/hearts - but they could have been in process before.
I am attaching photos. Since the root rot, I have been watering only once a week (from March until I noticed the root rot I was watering twice weekly) I use 20-20-20 fertilizer each time I water. First I let water run through the plant, then I water with the fertilizer mixture. I've been doing this since I got the plant. I move it around a bit to keep it in bright, indirect sunlight. It's possible that it gets some sunlight that is more direct than indirect - I'm not completely sure about the dividing line. Earlier in the spring I was putting it out in the mornings in dappled shade and this helped multiple spikes to grow and it flowered beautifully.
It seemed to get sick about the time I started keeping it inside to avoid 100+ heat and using my swamp cooler. I live in Tucson and it is usually dry but Monsoon Season is starting and humidity has really kicked up as well.
I would be so grateful for help with this - it seems like it is probably a fungus of some type?
yellowish/tan splotches on Oncidium leaves
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