Phalaenopsis with leaf problems - sunburn or worse?

[Pulelehua]

I'm looking for help with a phalaenopsis that has tremendous sentimental value to my daughter-in-law. It was given as a gift 8-9 years ago to her grandmother who recently passed away. We call this orchid "the Queen" because she is quite large and produces an abundance of huge white flowers. She seemed to be flowering herself to death (9/16 - 2/17), branching from flower spikes with buds, prolonging any opportunity for re-pot.

I suspected she was in distress because she had not been re-potted in almost a decade. It was in a green plastic pot, so I could not see how the lower roots were doing, but the newer leaves are smaller than the others and there are also what I thought were sunburn spots on several leaves due to her being left outside for a month last summer. When her flowers eventually began to droop, my daughter-in-law brought her to me for help.

Using sterilized clippers, I decided to cut her remaining flower spikes to encourage root and leaf production instead of flowers and treated with cinnamon. After removing the green pot, I found mostly sphagnum, especially packed in the center. All lower roots were rotten so I removed them. There is a rather long base stem that was hard (not mushy). I felt I had traumatized this orchid enough in its already weakened state, so I decided to leave the stem for some support. I sprayed generously with hydrogen peroxide and allowed to dry completely before potting in only bark medium in a clear pot with side aeration holes. I watered initially and then weekly and placed in an east facing window with no direct sunlight. We are in a warm climate even in winter (60's and 70's at night / 70's and 80's during the day). At last check, we have 80% humidity.

I've noticed the 2nd leaf from the bottom (with what I thought were sunburns) is now turning yellow and is soft. I'm worried that I did something terribly wrong during re-pot or that the spotted leaves are a symptom of a larger problem.

Would someone please help me save this poor orchid?

[jkofferdahl]

I think something is eating your plant. Were it mine I would unpot it, treat it for insects using what ever method you prefer (I like any insecticide that works) and then repot it. After 10 days to 2 weeks, treat it again, then once more in another 2 weeks or so.

To keep insects off my plants I regularly dust with diatomaceous earth.

[estación seca]

First, Welcome to the Orchid Board!

I think your repotting job looks wonderful.

The yellowing of the bottom leaf is probably an old leaf reaching its end of life. Sunburn would more likely affect more leaves, not just one on the bottom, where the other ones shade it.

Watering in the new pot and new medium is going to be very different than when it was in 9-year-old moss. The idea is to water, then let it get just about dry at the center of the pot. One way to tell whether it's dry is to use a wooden cooking skewer:

Using skewers to determine when to water

The tiny pits on the leaves - I don't know. It may be insect damage. It may be fungus or bacterial infection. All three of these are common in humid places.

I would ask an experienced orchid grower who lives near you. This may be a common problem with plants there, and they will know what to do. If you live in Hawaii, there are a lot of orchid clubs and orchid sellers who can help you.

[Pulelehua]

Thank you so much for your responses! I will take your advice and try to find someone locally to bring the orchid to. I hesitated to go that route because I don't want to spread any bacteria/fungus/virus, if that's what is going on.

I have been washing the leaves periodically with a wash to help protect against insects that I got from one of Brad's Greenhouse YouTube videos - made up of 1 tsp environmental friendly dish soap, 1 cup isopropyl alcohol, and 1 cup distilled water - and a paper towel.

The pit marks have not increased in size or number since the orchid was outside for that month last summer (August). My daughter-in-law was traveling, so the orchid's only hydration for that month was from sporadic rain. One of the leafs has a split in it. Is it possible that the pit marks and split are from heat exposure or dehydration? Or is it more likely that something was eating it while it was outside?

[estación seca]

The split is from drying, but the pits are something else.