Question
Hi Will,
  I seem to be having some trouble with Kentia palms.  I can't fiugure out if it's the Brand "X" I have been using, the Dyna Grow fertilizer, or the Oxygen Plus.  I have been combining the Dyna Grow fertilizer with the Oxygen Plus (50/50 mix) and adding this to our watering tanks.  We also spray the Kentia palms and Bamboo plants with Brand "X".  Both the Kentia Palms and the Bamboo plants are showing signs of yellowing in their leaves while the other plants we service don't show similar problems.  We're trying to isolate what the problem may be - any professional experience you have with any of the above products would be appreciated.  The Brand "X" is being mixed at a ratio of 5 ounces per gallon (recommended ratio is 4 to 6 ounces per gallon).  Thanks!

Jennifer

Answer
Hi Jennifer,

There used to be an ad campaign for DuPont with a tagline, "Better living through chemistry!" It seems you are applying that to your plant care! LOL! I have no objections to using chemicals and do use them on occasion, but I don't believe they often make much difference.

Although you didn't indicate it, I will assume that you are working as a professional plant maintenance technician because few non-professionals know about the products you described. Please let me know if I am wrong because I am also assuming that the Kentias are getting proper light, are properly potted, and are properly watered.

I use Brand X as a leaf shine and as a treatment for mealies and scales. I like it, but I rarely use it more than once on a plant. I have seen some increased leaf drop on Ficus benjamina after using Brand X, but otherwise no leaf yellowing on other plant species. I have not used it on palms because mine are usually purchased clean, don't benefit from leaf shine, and almost never have scale or mealy problems. It is possible that repeated applications of Brand X could cause leaf yellowing, but I doubt it.

I use Dyna Gro's Foliage Pro in dilute form for plants that are in good light conditions and only on a monthly or bi-monthly cycle. At low doses, I am confident that it does not cause any leaf yellowing. Moderate doses in low light (where Kentias are often located), over an extended period of time might cause excess mineral buildup and leaf yellowing. I don't know if that applies with your palms. In fact, I don't know which Dyna Gro product you are using.

I have not used Oxygen Plus because I have never been convinced that it is a substitute for proper watering. If you allow plants to dry out properly, then added oxygen should not be necessary.

I suggest that you stop using all of the named products on the affected palms. The benefits that they provide are marginal at best and if you suspect they are causing leaf yellowing, then it makes sense to stop using them and see if there is improvement.

It may well be that inferior quality plants (especially with Kentias), inadequate light, and improper watering are the real culprits.

I hope this is helpful to you. I would like to know what company you work for and in what market (Don't worry, I will respect your confidence).

Please let me know if any of this is unclear or if you have any additional questions.

Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

You can E-mail me directly at: [email protected]

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