Question
Hello, please help!
Here's my problem - I received an orchid as a gift, the pot states that it's a phalaenopsis, however the tab in the plant said cymbidium.  
It has white and pink petals, the pot is 13L, 3 stalks, leaves are dark green.  The plant sits on a table between 2 windows, not getting direct light, but still getting daily sun.  I water it once a week and live in Atlanta, with med humidity so far and temps in the 80's.
My problem is that suddenly the petals just started dropping like flies.  I know they do this occasionally, but it seems very sudden.  In addition, there is a small black spot under one leaf (fungus I assume), and the petals start getting like a dirty grey color on the outsides.  
Please, please, please, if there is any information you can give me, any advise, anything, it would be well received.  And should you need any additional infomation, I will do my best to supply it.  

Thank you!
Krista

Answer
Hi Krista

Let's first see if we can determine which type of an orchid you have.  Cymbidiums have grass-like leaves many times longer than wide.  The leaves are also quite thin and tend to droop because of their length and thickness.  On the other hand, phalaenopsis leaves are fairly thick and not much longer than they are wide.

It does make a difference in terms of growing.  Cymbidiums like to be summered out and can take temperatures as low as into the 40's.  They do well outside on a north facing location.  Phalaenopsis, on the other hand, are house plants and like fairly uniform growing conditions (ie 65-85 degrees F.).  They prefer an east facing window where they get a little morning sun.

Both types of orchids bloom only once per year. Each flower last 2-4 weeks. I don't know how long your plant was in flower before it dropped its petals. Excessive heat or cold can affect premature flower drop.  Also, a plant that is in flower and experiences a major change while in flower can be stressed and lose some or all of its flowers.

The black spot under the leaf is likely a fungus.  You can remove that portion of the leaf that has the black spot to prevent spread.  The dirty grey color on the flower petals is likely an early stage of flower ending.

These plants like to be repotted in fresh orchid potting mix when new growth starts.