Question
Dear Mr. King,

My husband has an orchid that he used to keep in a glass vase.  Despite the nonvented container, the orchid did relatively well.  

We recently moved and repotted the orchid into a vented plastic container. Some roots at the bottom seemed rotted but the ones on the top were not.  The orchid continued to bloom, but the leaves became brown/yellow and fell off.

The single stem is still green about 5 inches up from the base, there is a green leaf starting to grow at the base, and there are about 5 strands of roots that appear to be alive at the top of the base near the leaf.  However, all the other roots seem to have dried out even in the soil.  

What should I do to nurse it back to health?  Should I repot it?  If so, should I keep all the healthy-ish roots above the soil?  Would it be okay to cut off the dried out roots below?  My concern is that there would then be barely any base on which the orchid could be rooted into the soil.

Thank you for your expertise!

Answer
Thank you for your questions Alice.  It sounds as if growing the orchid in the unvented container kept the roots too wet, resulting in root rot.  In addition to growing in a plastic container, it is good practice to repot the plant after each flowering in fresh orchid potting mix.  Orchid roots, unlike most other house plants, need to have air movement through the potting mix.  Naturally, they grow with their roots exposed to air that is moist or humid.  I recommend that you unpot your plant, rinse off the roots and remove any that are "mushy" as these are dead, and repot it in a fir-bark based commercial orchid potting mix (you can find a couple of types at garden centers in Home Depot, Lowes, or any place that sells orchid plants).  It is good practice to soak that portion of the potting mix you plan to use before using it.  This is because fir bark repels water when dry.  In repotting, use a container that is just the right size for the remaining roots (healthy roots are firm and turn green when wet).  Place the plant in the container and add potting mix, tapping the pot to distribute the mix among the roots.  The base of the plant should be even with the top of the potting mix.  Dried out roots usually are not a problem.  Roots develop as cork-like covering-- especially when on the surface or outside the pot.  This prevents moisture loss.  You may place some of these aerial roots into the pot but this should only be attempted only if they have been soaked as they tend to be quite brittle and could break.  There is no problem in leaving them outside of the potting mix if you don't want to take that risk.  Try to let the potting mix dry out between watering and then soak the potting mix thoroughly with each watering.  Do not let the pot sit in water as this will keep the potting mix too wet.

It sounds as if you have a new plantlet (called a keiki) growing at a node (ie joint) on the flower spike.  If the old flower spike remains green, this can develop into a mature plantlet with roots, leaves, and may even flower.  Most growers like to remove this keiki when it has new roots and pot it into a separate container.  Always use a container that is appropriate for the root mass.  Too large of a container results in the potting mix staying wet too long.  If you have an east facing window, the phalaenopsis orchid would prefer the morning sunlight that provides.

If my suggestions raise further questions, feel free to ask anytime.