Expert: Wayne King - 10/22/2009

Question
I have an cymbidium orchid that is about 50 years old. It was in a large wooden planter box.  It suddenly dying leaves turning brown and wilted. Many of the bulbus base is spongey.  There is still some green bulbs.  When I re-plant how do I pull dead areas away form existing healthy roots.  What type of soil should I re-pot it in.  It was in a very sandy soil.  Should I use the same type of soil or get orchid mix?

Answer
Nicole, that is one incredible cymbidium.  You didn't mention how long it has been since repotting. I suspect that it has been quite a long time.  A cymbidium of that size would take quite an effort to repot. I recommend that you repot using a standard orchid potting mix (you may add a limited amount of sandy soil to avoid changing the root environment too radically while maintaing a sufficiently open mix to allow air flow to the roots).  You will need to separate out those pseudobulbs that are soft as rot is setting in and could spread to the healthy bulbs.  You can simply pull the bulbs apart or use a sterile cutting instrument to cut the rhizome at their base. You may remove clusters of healthy bulbs or remove only the soft bulbs-- the latter of which should be destroyed.  Either way, you may end up with several clusters of good pseudobulbs which can be separately repotted. Be sure to seal the cut ends with a powdered fungicide such as roottone or powdered sulphur.