Diseased orchid? Fungus? Cymbidium

[dubeage]

We received an orchid about seven months ago. Over the past couple of months, some of the leaves have turned yellow and died. I've also noticed a powdery cream coloured residue forming on some of the leaves and at the base of the bulb that all the leaves had died on. The orchid is kept indoors 100% of the time in a 15 celsius environment. I know nothing of orchid care.

[JungleMel]

It's hard to see, but the white stuff looks like mold. Possibly you're over-watering it or the media is breaking down and rotten. It's hard to diagnose what the problem is without more information, how do you care for it? What kind of light, watering, potting media, etc. It looks like the mold is only on the dead leaves, feel free to cut them away. How fast was it losing leaves? Like any other plant an orchid will shed old leaves as it makes new ones.

Also, here's a culture guide from the AOS on cymbidiums:

AOS Cymbidium Culture Sheet

[dubeage]

THANKS! We really like our orchid and want to treat it well but have never had one before. The potting media is the same what we got it in. It was store bought to my knowledge. We haven't changed it or altered the soil in any way since receving it. It gets light daily but winter in the Canadian Rockies doesn't provide an overabundance of it. There is 'mold' on the base of the 'dead' bulbs and on the living leaves. I've removed the dead leaves. We don't water it as frequently as the other plants we have as we were told not to. There still is new growth but no spikes since the first time we got it. The culture sheet has a lot of stuff I didn't know so that helps too, thanks again.

[JungleMel]

No problem, glad it was helpful! Is your humidity high? Possibly, it's a fungus or mold if it's on healthy leaves too. You could always take some alcohol and wipe it off, see if it comes back. Is the white on the media as well? Either way it's always recommended to re-pot in fresh media when you get a new orchid. This way even if the media isn't decaying, you can at least check the condition of the roots and get rid of any pests that might've crawled in.

I'm no cymbidium expert, maybe someone with more specific knowledge will chime in on this, but it seems as if a temperature drop in the winter is the critical factor for re-blooming, and that may only happen once a year if temps. are in a good range for them. So it would make sense, and is expected, that it's not growing much for you right now anyway. Good luck with it!

[dubeage]

Thanks again, no humidity here, very dry. What type of alcohol should I use? An over the counter general type disinfectant. I've never used alcohol on a plant before. I've got some Root Beer Vodka over here, but I don't think you meant that...

[JungleMel]

Isopropyl alcohol, the kind you'd find at a pharmacy. Saturate a cotton ball or tissue and wipe over the leaves. It will evaporate quickly enough to not damage the plant.