Question
I purchased a whole batch of denrobium orchids which look healthy enough.  I've had them (I live in a very sunny New York City apt.) for several weeks and I see that many of them are gettng extremely yellow leaves.  I water them once a week and never leave them sitting in water.  Can you tell me the cause and how i should fix it?

Thanks,
Pat

Answer
Hello Pat,

The yellowing of leaves may be due to too much sunlight.  Try moving them about 3 feet from the sunny window and they may green up a little.  Dendrobiums love bright light but not bright mid day sun, early morning or late afternoon is fine.  You can also try placing a screen or sheer curtain over the window to reduce the light intensity.  As summer approaches, the light intensity will grow stronger so either move them further from the window or place them in an east window.  

Hope this helps.  

Jim Kawasaki
San Jose, Ca.