Question
QUESTION: Hi Wayne--
I have moon orchid (or at least that's what I was told it was) whose existing
leaves are turning limp as a new leaf is growing. Is this normal? I know the
lower leaves drop off but recently the stronger leaves are also looking limp.
Do we need to increase watering during new leaf growth? We haven't been
using an orchid food should we start during new leaf growth?

Thanks for the advice!
--Annie

ANSWER: Annie, Moon Oorchid is the common name for a phalaenopsis species (phal amabilis).  This orchid has a root problem and needs to be repotted.  You will need to find a commercial grade of orchid potting mix that is fir bark based.  Better Grow is one brand sometimes carried by garden centers, including Lowes and Home Depot.  When you obtain a small bag, soak a portion of it while you unpot your plant.  Rinse off the plant's roots and discard the old potting mix.  If any of the roots are mushy, they need to be removed.  Only firm roots are healthy and will be the basis for future growth of your plant.  You may lose some leaves because the roots providing nourishmnet to those leaves are dead or dying, Orchids need an open potting mix to allow air to pass through the mix because, in nature, these plants grow on trees with their roots exposed to air.  When repotting use a plastic pot with losts of holes in the bottom to permit good drainage and air movement. When repotting, after the roots have been placed in the pot, add the wet potting mix and tap the pot to allow settling about the roots.  Do this in an area where the excess water can drain off.  It will be a month or more before new roots begin to replace old ones and new leaves begin to emerge, so be patient.  This process should be repeated after each flowering.

After repotting, water once per week and, when new growth starts, you may feed it with each watering with 1/4 tsp of plant food per gallon of wwater.  Place the plant in an east facing window if you have one.

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

QUESTION: Hi Wayne--
Thanks for the info but I have a few contradicting details to your message.

This plant has a new leaf currently growing, and is actually still flowering on a
secondary spike (the primary spike has finished flowering). We're also seeing
new root growth on the top layer of roots.

I did not repot after the primary spike finished flowering because I was
waiting on the secondary spike to finish, but a new leaf & roots popped up
before any of that happened.  

Would you recommend repotting with this new growth happening?  Should I
begin adding the plant food instead?

Thanks
--Annie

Answer
Annie, normally I recommend that a plant not be repotted until it finishes flowering.  The reason is to provide maximum enjoyment.  In the case of your plant with limp leaves, I think it's advisable that you repot as soon as possible.  The fact that you have new leaf growth is a good thing since it is an indication that you still have one or more good roots. Phalaenopsis are, more or less, in constant growth and don't have a rest period the way many orchids have.  When you repot, you can just leave the flower spike on and be sure to stake it after repotting.  The repotting will not set the plant back, but it will take a month or so for it to develop new roots which will then support additional leaf growth. In the meantime, repotting should also help prevent additional, healthy leaves from going limp.   You may feed the plant after repotting but use a dilute solution of plant food (ie 1/4 tsp per gallon of water).  Many times, the appearance of new roots on the surface of the potting mix indicates a sour potting mix and the plant is trying to avoid sending it roots down where they will die.