Question
QUESTION: My phaleonopsis that I've had for several years has developed black mushy spot on the base of the plant near the bark.  I recently moved it to a large bathroom with an east window.  Two leaves also died.  I hope you can help.  Thank you!
Sue

ANSWER: Sue, you failed to mention how long ago you repotted the plant.  Orchid plants need to be potted in a special orchid potting mix and phalaenopsis orchids should be repotted after each flowering.  The most common problem encountered with phalaenopsis orchids is root rot due to either a failure to repot or to using the wrong type of potting material. Before looking at other issues, let me know what you have done in the way of repotting.  If you are unsure about the repotting process, send me a followup and I can walk you through the process I prefer.  If you have a picture you can send, that might also be helpful.

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QUESTION: Thank you for responding so fast!  I have never repotted my orchid.  It has bloomed several times. The last being a few months ago. Attached is a picture.  I also have another orchid that is just finishing blooming.  If you could help me with the repotting process that would be great!
Sue

Answer
Happy to help Sue.  There are three main aspects to this process.  First you must locate and purchase a bag of orchid potting mix.  It should have some fir bark in it but also some bits of perlite, charcoal or other inorganic ingredients.  The inorganic particles do not decompose while  the fir bark will so these inorganic particles help to preserve air movement through the potting mix as the fir bark turns to soil.  Most places that sell orchids also have orchid potting mix including the garden departments of Home Depot and Lowes.  When you are ready to repot, you will need to soak the orchid potting mix because dry fir bark repels water and soaking the pottingm mix will help to break down the repellancy.  You should soak it for an hour or so prior to use for repotting.

The second step involves unpotting your plant.  Once you have removed the plant from its pot, toss the old potting mix and rinse off the roots.  You likely will find some good, healthy, firm roots and some that have collapsed.  The collapsed roots are dead due to the decomposed potting mix and these should be removed prior to repotting.  Orchid roots consist of a central root hair surrounded by a spongy area called he velamin which takes up water and minerals from the potting mix and stores it for transport by the root hair to the plants leaves and other growing parts.  Once this velamin has collapsed, the root serves no useful function.

The plant should be repotted to the proper size plastic pot with lots of drainage holes in the bottom and/or sides.  The size of the needed pot will depend upon the extent of healthy roots to be repotted.  Roots tend to follow the inside walls of the pot as they grow and, hence, form a ball which comes unravelled as the roots are removed from the pot.  If you have a root mass to be repotted, you will need a pot that is an inch or two larger in diameter for repotting the plant.  If, on the other hand, you have had to remove quite a few collapsed roots, you may be able to repot the plant back to its same pot.  If you have one or more fairly long roots to get into the pot, slowly rotate the empty pot as you lower the root mass into the pot.  This will allow the roots to follow the inside walls of the pot (just as they did before you removed the plant from its pot) and minimizes damage to the remaining healthy roots. Be sure  to have the new pot and plant to be repotted in an area where water can drain off as the fresh potting mix will be wet. Slowly add the potting mix as you lower the roots into the pot, tapping the pot as you do so to help the new potting mix to settle amonst the roots.  Try to cover all of the roots with the fresh potting mix.  Water the roots into the fresh potting mix and set the repotted plant aside to drain for a day.  The you may remove it to its growing area and withhold water for at least a week or until the potting mix is dry to the touch.