Orchid leaf yellowing – House Plant Journal

Orchid leaf yellowing

Plant Parent

I’ve been trying my hand at Phals and enjoying it but my first challenge has arrived! I bought an orchid in full bloom from a garden store in December. I’ve just now noticed that it has a yellowing leaf.

This leaf looks to be the third oldest out of eight and because the other ones are healthy, I’m wondering if something else is going on. What do you think? A case of “let nature take its course” or is there something I can do to help my Phal?

Additional detail:

  • I haven’t repotted, just cleaned up some fungus and dusted leaves with damp tissue occasionally.
  • The yellowing leaf appears to start breaking off (can’t tell if it’s from a previous mechanical injury or health issue).
  • This is next to other tropicals and close to my south facing window.

Darryl

Can you tell me how you’ve been watering? Please let me know your thought process on how you decide to water and your specific method(s) for re-wetting the planting media.

Plant Parent

I check the roots and wait until they’re silvery (been slower in the winter so about 3 weeks). I pour water slowly around the edge because I’ve seen what crown root can do to an orchid and I’m so afraid to encounter it again. It’s weird that it’s happening to this one leaf.

Darryl

If most of the indirect light hours of the day, your plant is getting 400 lux (approximately 40 fc), that’s way too little light.  By moving the plant to where it will have the widest possible view of the sky (that is, right up close to the window, with no blinds), you should be getting closer to 400-800 fc (or 4000 – 8000 lux) for indirect light and, during direct light through a window, 3000-4000 fc (30k – 40k lux), and this can last 2-3 hours and orchids will be fine.

Light requirements (in foot-candles) for various plants here.

Since your orchid has a plastic pot with drainage holes, you should be watering by thoroughly soaking the entire planting medium and letting the excess drain away.  Nice even moisture is what you’re aiming for when watering plants.

Crown rot only happens to weak plants.  Plants become weak when they are starved for light, far from windows.

The yellowing leaf is likely due to nutrient limitations but I wouldn’t be concerned – Phalaenopsis live just fine with 3-4 leaves.  Just pluck off this leaf once it becomes fully yellow and thank it for its contribution to photosynthesis!

Plant Parent

Thank you so much Darryl, that really helps me rest easy. This is such a great service you’re providing and I very much resonate your philosophy with plants!

Darryl

My houseplant philosophy in a book…

Tired of your houseplants dying on you?

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