Question
Hello. I received a very large cymbidium in full bloom in April for my birthday. The blooms lasted until the end of July. It started growing 5 spike or bulbs (I can't tell the difference). In August and over September I noticed that some of the leaves started turning brown from the bottom up and falling off. So I moved it to a shadier position which slowed this down but they still turned brown. Then in  September I noticed that the compost was going a bit mouldy so I bought some new orchid compost at the end of the month.  and split the plant into three parts, 1 big section and two smaller ones. A lot of the roots were soggy and dead as the bottom of the pot appeared to be waterlogged.

Unfortunately the new compost has turned out to be infected with flies. I have been spraying the plant every few days with insecticide but the two smaller divisions appear to be dying. The leaves are rapidly turning  brown from the bottom off and the new growths have turned black. In one of the pots there is a bit of mould in the compost.

The bigger section appears to be ok and looking healthy but today I noticed that there are dark lines across the leafs near the bottom of the plant. On the other sections, the leaves got these marks and broken along these lines when they turned brown.

Is there anyway of saving my plant? Im not sure if I should repot it again or continue using pesticide. Also I used to water it once a week and I am now watering it once every two weeks - is this correct?

Answer
Hello Roxane,

From your description of what is happening to your cymbidium, my guess is that it may be due to watering it from overhead.  You did not mention where you live or where and how you are growing it but my guess is that you have it indoors.  Cymbidiums are one of the orchids that grow best when outdoors getting lots of light and air movement.  

The soggy dead roots indicates that it was kept too wet over too long a time.  It also sounds like the potting media had broken down which lead to the dead roots.  What kind of compost did you buy to repot with?  Cymbidium roots need to have some air around them, therefore a somewhat loose potting material should be used.  Never use a soil type potting mix.  Look for one that is composed primarily of orchid bark with maybe some other materials too.  

Here are some guidelines on cymbidiums: lots of sunlight or enough that the leaves will be a light to medium green color, dark green means too little light while yellow-green too much.  Humidity above 40%.  Temperatures between 40F to 85F, even to 30F and upwards of 100F if given some protection.  Water when the potting media becomes barely moist and feed it a balance type orchid fertilizer regularly.  A really healthily growing cymbidium can be watered more frequently but a sick one you need to be more careful and mindful about watering.  

As for saving your cymbidiums, the two smaller ones could be difficult but I'd suggest concentrating on the larger one.  Check to make sure the pseudobulbs at the base of the leaves are nice and firm when squeezed, if the are even slightly soft they probably are goners.  If the larger one is still okay, get your potting materials ready and repot it.  Follow the guidelines from above on how to care for it and hopefully it will survive and produce blooms for you.  Just be patient as it may take several years to do this as it needs to first recover then start growing.  

Hope this helped.

Jim Kawasaki
San Jose, Ca.