Question
I am desperately seeking advice about my orchid.  I received a Phalaenopsis orchid in the beginning of May and it was doing wonderfully.  It has two stalks and two branches coming off each stalk.  When I first purchased it a few flowers were bloomed with numerous buds on it.  Immediately the buds began to bloom and flourished until the beginning of July.  At that point one of the stalks blooms began to wither and all of the flowers have fallen off.  The second stalks blooms have stayed perfect without any change until this week when they have began to wither and a few have fallen off.  I also noticed today out of the 5 beautifully green leaves this plant has, 1 on the bottom has yellowed and fallen off, while another leaf on the bottom is beginning to yellow.  The three upper leaves still seem vibrant and firm.  The stalk which has no more flowers on it has begun to look dried out and almost yellowish.
   My orchid is in painted ceramic pot and is planted with moss.  I have not checked to roots or taken the plant out of the pot since i have it.  Actually it seems that one of the roots is growing completely out of the pot but looks healthy.  I have been very careful about watering and only water it when it is almost dry, although one time i do believe i over watered it and it was moist for almost two weeks, this is also around the time when the trouble began.  In that instance when i realized i must have over watered it i did drain the excess water and wait until the moss was almost dry before watering it again.  I do live in NYC and keep the orchid in indirect sunlight with warm temperatures in the day and cooler at night, as it is the summer and i sometime put on the air conditioner.
   My question is, is my orchid dying?? What can I do to ensure its survival?  Should i repot it as soon as the remaining blooms have dropped?  What is the best material it should be potted in? Should i crop the stalks?

Thank you for all you advice in advance!! It is greatly appreciated!! I hope I can save my orchid, I have become very attached and interested in the plant and hope it will have a long lifespan.  

Answer
Amanda, I'm glad you wrote when you did.  First, I wouldn't be concerned about the end of flowering. It is not unusual for flowering to last 6-8 weeks. Also. it is not unusual for flower spikes to die back after the end of flowering.  While the loss of a lower leaf or two could be normal, if it continued beyond that point, it could indicate root rot. My experience suggests that moss is not a good long term potting material for phalaenopsis orchids and ceramic pots generally do not have enough drainage to promote good air movement through the potting mix.

As a starting point, I recommend that you purchase a good fir bark based orchid potting mix. It need to be a potting mix that contains perlite, charcoal as well as other ingredients to provide an open mix. Such dry orchid potting mixes need to be damp or wet prior to use or they will draw moisture out of the roots.  Also, repot to a plastic pot with lots of drainage holes in the bottom and/or sides.

Remove the plant from its pot and discard the old potting mix.  Rinse off the roots thoroughly and examine them.  Remove any roots that are mushy as these are dead or dying.  Healthy roots are firm and will turn green when wet.  The final step is to insert the healthy root mas into the new pot.  This is best done by slowly rotating the pot as you lower the roots into the pot.  Add the potting mix slowly to the pot, tapping the pot as you add it to help it settle about the roots. When finished, be sure the crown of the plant (where the leaves originate) is slightly above the potting mix.  You may cut off the old flower spikes when the flower spike starts dying back.  Place the repotted plant in a place where it can drain and do not water it for at least a week.  Then water every other week until new leaf growth starts and you can then water weekly.  You may feel free to ask followup questions as you proceed.