Question
I acquired a 9' tall corn plant that's 20 years old.  It was in a very root bound 24" pot, I repotted it into a pot about 30" a few months ago.  The plant began deteriorating right after I got it, not after I repotted it.  Although there are new leaves that appear healthy on top, they're not growing fast and the older leaves are not doing well.  They are browning out on the edges and tips.  The plant is on my back porch facing North where it gets indirect light.  I live in Houston, TX. I've been watering weekly with about 1/2 gallon of water, and fertilizing with a very small amount of Peters every two weeks.  My water has a high PH...This was continued as per the former owner.  What should I do?

Answer
Hi Craig,

The alkaline water is definitely a problem and is causing the browning of the leaf tips and margins and may also be causing some of the leaf yellowing. Use filtered or distilled or rainwater instead.

Your corn plant may be responding to a change in light. You didn't describe the light it had with the previous owner, so I cannot be sure except that any significant change in light will cause lower leaf discoloration.

Repotting into a larger pot rarely helps any ailing plant and very often aggravates other problems. That may be a contributing factor, depending on your repotting technique (Did you loosen the roots? What kind of potting soil did you use?), and whether you are now keeping the roots too moist.

Plant food is for healthy plants tha are growing vigorously. If the soil pH is too high the nutrients cannot be absorbed anyway. Get the pH in the 6. to 6.8 range and stop fertilizing until the plant has returned to full health.

I am sorry I cannot give you one specific cause for the plant's problems, but it may well be a combination of some or all of the aforementioned.

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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