Question
QUESTION: I have a number of cymbidium orchids and have a recurring problem with black leaf tips.  I have tried more and less often watering, with no significant change in these occurrences.
I was you note on epidendrum leaves; does that apply to cymbidiums also?

I live in Southern California and the plants have about a have a day of full sun, and partial the remainder.

ANSWER: Hello Arnold,

The short answer is "yes".  

Black leaf tips is usually caused by excess salts in the water along with the excessive use of some fertilizers.  To minimize black leaf tips, once a month water them twice with plain water spaced about 2 hours apart.  When watering, make sure to run twice the pot volume of water through the pots.  The first watering will loosen and suspend the excess salts and the second watering will flush it out.  If you prefer, you can add fertilizer to the second watering.  

Depending upon where in So. Cal. you live, half day full sun is about right as long as it is not all during the middle part of the day.  

Hope this helped.

Jim Kawasaki
San Jose, Ca.



---------- FOLLOW-UP ----------

QUESTION: I use the Orchid Food Red 30-10-10 during growing season & Blue 6-30-30 for flower stock stimulation.  Usually 2-4X per month.  Is this excessive?

Answer
Hello Arnold,

The orchid food you are using is one part of the problem causing the black leaf tips, the other may be the water.  

If the nitrogen in the orchid food is mainly urea rather than nitrate or ammoniacal nitrogen, that could be contributing to the problem.  If your water supply is considered hard water or high in salt, that in combination with the orchid food is slowly causing the leaf tips to die back.  

How this is happening is the urea takes a long time to break down into a form that is usable by the orchid and settles near the bottom of the potting media, this in combination with the high salt level of the water gets taken up by the roots.  Eventually the salt works its way up the leaves but when it reaches the tip or end of the leaf, the salt collects there and kills the leaf tissue leaving the tell tale black tip.  

As for the frequency of feeding, I prefer feeding at each watering but with less fertilizer, I only use about 1/2 to 1/3 of the suggested amount on the label.

The best water for orchids is rain water but you would have to collect quite a bit of it to water your orchids regularly unless you happen to live in an area where it rains year round.  Or you can minimize the affect of your water by double watering once a month.  

Hope this helped.

Jim Kawasaki
San Jose, Ca.