Question
Hi - I have two orchid plants, that I bought a year ago in bloom, sitting on
opposite ends of my kitchen sink, at the edges of a northwest-facing
window.  The smaller of the two put out four nice blooms a few weeks ago,
but the larger one's bloom stalk has been slowly turning yellow and
withering.  But it is growing several healthy-looking root tubers.  I think I am
watering properly, and they sit on gravel in the pots, though I haven't
fertilized.  Please advise what changes I could try.  Thank you - Carina

Answer
Carina, some phalaenopsis hybrids are genetically predisposed to have the old flower spike die back.  It sounds as if this is what you have on the larger plant.  With this type of phalaenopsis orchid, you will have to await the production of a new bloom spike from the base of the plant. You may cut off the old bloom spike. The "healthy looking tubers" may be aerial roots or may be the start of bloom spikes.  If you can send a picture, I might be able to confirm which it is.  Otherwise, patience alone will answer the question of hwether these "tubers'are roots or flower spikes.