Question
Hi!  Several years ago, a friend gave me a large cymbidium from the office which had finished blooming (so they were getting rid of it!).  We divided and repotted the sections in four pots.  Over the last four years, each plant has bloomed, but not every year.  In each pot there are some fat stems/bulbs with very long green leaves and some dead, dried up pieces.  I have a couple of questions.  First, I read that you advise against cutting the leaves; some of my leaves become so long that they flop over and crease and then become brown at the crease.  I generally cut these off at the crease, but would appreciate further clarification on the leaf-cutting issue.  I imagine that they need to be repotted, no problem.  How can I encourage them to bloom?  They can spend the summer outdoors here in humid MA, but are really too big to be my screened porch.  I can provide high dappled shade, half-day light (southeast) or full south facing light (which I assume to be too strong).  Where should I summer them?  Also I read that you recommended epsom salts for Phalenopsis -- same treatment for Cymbs?  Are they heavy feeders?  I haven't fertilized much, sorry.

Answer
Hi Susanne,

You've done a pretty good job with the cymbidium thus far, congratulations!  

First a couple of questions then some answers or suggestions.  When you repotted and divided the cymbidium, what size were the divisions?  It is best to have a minimum of four bulbs with leaves per division to minimize the shock and recovery from dividing.  Those dead dried up looking bulbs are called backbulbs and are still alive and useful to either help a division of less than 4 bulbs with leaves or individually to increase the number of cyms you have.  Those backbulbs may have dormant growth eyes and if you pot the individual bulb into a pot, the eye may start to grow and eventually grow to be the same as the mother cym.  This is a slow process that may take upwards of five years before it produces blooms.  

Yes, I do not recommend cutting off the leaves other than to get rid of any unsightly leaves.  If your cyms leaves are bending over causing a crease, it may be that you should increase the watering, especially during the warmer months.  

As for repotting, how often depends upon what type of potting medium you use, how often you water, how often you fertilize and what type of fertilizer, plus a few other things.  Most potting media will need replacement from one to three years.  To determine if yours should be replaced, try smelling the media a few days after watering to see if you detect a sour odor, if it smells sour it needs to be replaced.  

Once day temperatures remain above 45F, you can move the cyms outdoors under light shading.  In the fall, wait until night temperatures are about 35F before moving them back indoors.  Epsom salts can be fed to them, mix it at 1 tablespoon per gallon water then water them three times a week apart in early spring and early fall.  During the rest of the year, it would be good to feed them with a balance type fertilizer recommended for orchids.  From spring through mid fall, feed them at least two times a month and about once a month through winter.  

A south exposure is best if you can give them some light mid day shade or dappled shade from a tree.  The same goes for a west exposure but they may be able to be in full sunlight for half the day in an eastern exposure.  

I hope this helped answer your questions.  If you have other questions or would like more information about the above, write back and I'll try to answer them.  

Jim Kawasaki
San Jose, Ca.