Question
Hello,

My cybidium orchards was passed to me by my husband's Grandfather and were once magnificent. For the last few years or so now they have been looking sad and not flowering.

They have developed a whitish, crusty coating on the leaves, that flakes when I run my fingernail over it. The leaves eventually yellow and dye, and I fear I will soon have no leaves left at all. The leaves I do have, despite being overtaken by the white crust, are a mid-tone of green.

The plants are positioned on a balcony where they get plenty of light. The same position where Grandfather kept them. I admit to not watering them often.

It is winter in Sydney, Australia and my orchids show no sign of flowering.

Please help!!

Megan, Sydney Australia

Answer
Hello Megan from Sydney,

This cymbidium must have a lot of sentimental value because it came from your husbands grandfather, I'll try to help you save it.  I'm not sure what the whitish crusty coating is on your cymbidium leaves, I've never seen it on any of my cyms.  But, if the white crust is on the underside of the leaves it might be boisduval scale.  Scale are sucking insects which can slowly suck the life out of an orchid, eventually killing it over several years.  Try soaking a soft towel or paper towel in some isopropyl alcohol and wiping the leaves, some or most of the scale should wipe off.  If they are scale, go to your local garden center and ask for a systemic insecticide for scale, mix it per the instructions and thoroughly water the cym with it.  It will take 3 separate applications over 3 weeks to eliminate the scale.  One of the problems with scale is what is visible is probably only a small portion of the total population as many more may be hiding within the potting media waiting their turn to come out.  

If you are not seeing spikes growing by now, it probably will not bloom this year.  Sorry.  

By the way, Sydney is a very good area for cymbidiums.  It appears where you are growing it that it is receiving good sunlight exposure.  It would be a good idea to be more mindful of watering it.  Keep in mind that when temperatures are hot (above 20C) it should be watered more frequently and when cold (below 10C) to water less often.  You didn't mention if you feed it fertilizer but it would be good to feed it once in a while, especially from spring through fall.  

Hope this helped a little.  If you find it is not scale, write back and I'll explore some other possibilities.  If you have other questions or would like more information, write back and I'll try to answer them.

Jim Kawasaki
San Jose, Ca.