Question
QUESTION: My phal bloomed, dropped the leaves and all was okay until the stem started to yellow.  I cut off the stem under the yellow after the next node.  However the yellow is continuing down the stem.  The other stem is still holding its blooms and looks fine.  What should I do?  I should add that normal care for orchid is weekly watering in a container where roots can never sit in water.  Thanks for any insight!

ANSWER: Heather, you have the type of phalaenopsis on which the flower stem naturally dies after flowering. You can cut it all the way back without affecting the plant. Your action to cut the flower stem above a node is correct for the type of phalaenopsis where the old flower spike remains green. I am concerned about your statement "dropped the leaves".  If you meant "dropped its flowers", that is fine.  Hopefully the plant's leaves are fine.  

Phalaenopsis plants need to be repotted in an orchid potting mix after the plant finishes blooming.  If you have no experience with repotting, let me know when the other flower spike drops all of its flowers and starts to die back and I will give you some pointers. In the interim, locate a source for orchid potting mix.  Home Depot and Lowes Garden Centers usually carry fir bark based orchid potting mix.

---------- FOLLOW-UP ----------

QUESTION: Yes, it was blooms that fell not leaves.  So I should cut the stem back all the way (say an inch or so)?  Also, I'm not currently in the US, so what should I look for in potting material or perhaps what shouldn't be in there.  There is orchid potting mix here.  Does the plant need a larger pot?

Thanks!

Answer
Heather, you may cut the old flower spike all the way beck to where it originates on the plant.  Then, when it reblooms, it will send up a flower spike from near the base of the leaves-- next year.

Most places that sell orchids also, in my experience, sell supplies including orchid potting mix.  Orchid potting mix contains some wood chips (fir tree bark), as well as other ingredients such as perlite, charcoal, tree fern, etc.. The mix has fairly coase pieces in it to promote air movement to the roots as well as some ingredients to help retain moisture and not allow the mix to dry out too quickly. If the nursery doesn't have orchid potting mix, ask someone there if they can tell you where you can obtain some. Whether the plant will need a larger pot depends upon the health of the root.  Over the course of a year (between blooming seasons) orchid potting mix can deteriorate.  When that happens, roots can die.  This produces mushy roots that are dead and these must be removed before repotting,  You will not need a larger pot if roots need to be removed due to decay.  If most or all of the plant's roots are healthy (ie are firm and turn green when wet) you will probably need a larger pot (eg an inch or so larger in diameter).  I recommend a plastic pot with lots of drainage holes when repotting.