Question
QUESTION: I have had success with all orchids - except Cymbids.  I found a standard cymbid that appeared healthy for some time until I transplanted it after a new pseudobulb browned.  Upon removal from its plastic original pot, I discovered that the rootsystem was so tightly wound around the base of the plant that it would not allow any water to penetrate to the center of the pot.  As a result, it was beginning to rot (fungal) from the inside out.  Much of the internal root system was broken and damaged while trying to remove the internal fungal decomposition. It was rinsed repeatedly and transplanted into fresh medium (clean pot) and placed back into the original lighting conditions.   
Post transplant, its pseudobulbs appear severely dehydrated despite being watered as usual.
Any thoughts?
Thanks in advance,
Worried


ANSWER: Hello Worried,

Basically, you did the right thing by repotting the cymbidium to find the cause for the problem but possibly for the wrong reason.  When a new pseudobulb rots, it usually is due to water collecting within the leaf folds and remaining there for days, eventually causing fungal rot.  When you unpot a cym and the rootball is massive and tightly wound around, you can cut off the bottom 3 to 4 inches of the roots with little or no harm to the cym.  This will make untangling the roots much easier along with your ability to get to the roots in the center.  When you cut the roots, try to allow 4 hours for the cuts to heal by leaving them exposed before potting it.  

Cym pseudobulbs can look a little dehydrated but if they are severely shriveling, that would indicate they are not getting much moisture.  What was the potting media you used to repot it with?  Does it allow water to drain through the pot while also retaining some moisture for the roots?  How quickly or slowly does it dry out?  Cym potting media should become almost dry between waterings.  

You did not mention where you live or describe what the growing area conditions are.  Cyms need quite a bit of sunlight in order to grow and bloom, depending upon where you live this can be any where from partial shade to full sun.  Most cyms should be grown outdoors as much as possible or until night temperatures drop below 35F.  The exception are the miniature or oriental cymbidiums which need more shade and slightly warmer temperatures.  

Sorry I could not be of more help but if you could write back with a bit more information, I might be able to better help you.  

Jim Kawasaki
San Jose, Ca.


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

QUESTION: Thanks so much.
Do you think that much harm has been done to a transplanted cym by not allowing the roots to dry after they were cut and rinsed?

With respect to the potting medium for transplantation, I used orchid mix, supplmentd with sphagnum.
What do you suggest is the most ideal?
The previous medium the cym was in was quite finer.
I live in Western NY and the plant has been in a West facing window for a while.
Any advice on how to encourage cyms to bloom?

Answer
Hi Worried,

The reason I said to allow the cut roots to air heal is because there is a slight chance they may rot if watered without allowed to heal over.  It is only a slight possibility though.  

It is okay to mix sphagnum in with the orchid mix but the problem with it is that it breaks down fairly quickly - about a year is the limit.  Cymbidiums do well in fairly loose potting mixes, usually ones made up primarily of bark with maybe some perlite or sponge rock and charcoal.  The main criteria is that what ever you choose to use that it be somewhat open to allow water and air to circulate through it.  In fact, it is possible to grow cyms in small sized gravel but that requires watering at least once a day if not more during hot weather.  

The old media may have looked finer due to age.  Most media will break down over time, becoming almost dirt like in appearance.  Orchid people are continually on the look out for new media for their orchids, ones that will last for years rather than months.  

Living in Western NY, a west window is fine but a southern exposure window would be better, especially from fall through spring as cyms really do need lots of sunlight during those seasons.  

How to encourage your cyms to bloom?  Have you tried getting on your knees and begging them?  (LOL)  Just joking.  I've already touched on light but didn't talk about leaf color.  When cyms are receiving proper light exposure, the leaves will be a light to medium green color, dark green means too much shade while yellowish leaves indicate too much.  Also, it is best to grow cyms outdoors if at all possible.  Cyms need temperatures down in the 40F's in the fall for 3 to 4 weeks to initiate the bloom cycle unless yours are the type that bloom in late summer to early fall, in which case they need the cool temperatures in mid to late spring.  Also, it may help to feed them a little epsom salt in the fall.  Yes, that's right epsom salt which is really Suphate of Magnesium.  In place of fertilizer, mix one teaspoon of e.s. in a quart or one tablespoon per gallon of lukewarm water then water them with it.  Do this for 3 or 4 waterings as the temps become cooler.  During the rest of the year, feed them a balance type orchid fertilizer at each watering but use half the amount suggested on the container.  Some people feed high N fertilizer from spring through summer then low N in the fall and winter but for only a few cyms I'd just go with the balance type.  

Of course, living in Western NY, exposing the cyms to sunlight in winter could be a problem but try to place them near a south exposure window.  If they get quite a bit of sunlight during the rest of the year, they should bloom for you but maybe not every year.  

This ended up being a little long but hope this helped.  

Jim Kawasaki
San Jose, Ca.