Question
QUESTION: My dieffenbachia (probably about 3 ft. tall) was doing fine until about 3 weeks ago when the lower leaves began yellowing and dying.  First it was just one leaf, but now in the last 2 days I've got one leaf totally yellow and two more on the way.  The plant was planted about 1.5 years ago from a cutting and has been growing rapidly, with about one new large healthy leaf per month.  I water the plant once a week and it has a nice southern exposure.  Would be greatful for any advice.

ANSWER: Hi Susan,

Yellowing leaves is a generic symptom with more than one cause. Improper light and watering are the two most common causes.

Dieffenbachia leaves tend to bleach to a pale-green/yellow color if exposed to sunlight falling directly on their leaves. If yours is close to a south window, then that is too much light for it. On the other hand, if it is more than 8 feet from the window, it may not be getting enough light.

Watering by a rigid schedule is convenient for us, but often not what a plant needs. The pot size, water volume, temperature, and humidity can all affect how often a plant needs water. For example, if the pot is too large (a common problem because people tend to up-pot too soon), the soil will not dry out within a week and the roots will slowly rot. The symptoms won't show up until much later. Likewise, not providing enough water may cause the soil to dry out before a week goes by.

If you can provide me with a photo of your plant, including its pot, I may be able to give you a better idea as to watering. In addition, more information on pot size, plant height, quantity of water added and temperatures would help me make a better assessment as to your plant's watering requirements.

I have written articles on Dieffenbachia care that I will email for free to you (or anyone else) who emails a request to me at [email protected].

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

If this information has been helpful, please click the Rate Volunteer bar below and enter a rating and nomination for me. I am a volunteer on this site so Ratings are the only compensation I receive for answering plant questions.

Need more information? Visit my website at:
A link to HorticulturalHelp.com

or email me at [email protected] or call me at 917-887-8601 (EST)
 
Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

Visit my website at: A link to HorticulturalHelp.com



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


susan-dieffenbachia  

susan-dieffenbachia-2   QUESTION: Thanks for your quick reply.  To answer your questions  My plant is 2'10" high and is potted in a pot 10" high and 12" in diameter. As you can see from the attached pic, it is slightly listing because when it was rooted, the stem apparently was not set straight in the pot, so it curves across the pot.  

I water with tap water, which is considered "hard"' about 300 - 400 ml,   once a week.

Susan

Answer
Hi Susan,

Thanks for the photos and additional information.

You may not have a problem. The plant looks healthy and it is quite normal for Dieffenbachias to lose their lower leaves as they add new ones on top. As long as you are not losing more than you are gaining over the course of a couple of months, it falls within the range of normal.

The pot is larger than it should be, but your watering volume may be okay. Allow the top two inches of soil to dry before adding about 400 ml of water. If it takes longer than a week for the top two inches of soi to dry out again, then add less water the next time.

Water quality can be a problem. If your water is hard, the excess minerals will eventually build to toxic levels for the plant. I suggest you switch to rain water, distilled or filtered water.

Even healthy Dieffenbachias are problematic because they grow tall, become top-heavy and need support to stand straight. They also develop bare stems at the bottom. The only antidote for this is regular pruning. The stem can be cut off at any point. New growth will emerge just below the pruning cut and grow upward from there. The top cutting can be rooted in the base of the existing plant so you will have two stems in the same pot, making for a fuller plant.

I have written detailed articles on pruning and Dieffenbachia care that I will email for free to you (or anyone else) who emails a request to me at [email protected].

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

If this information has been helpful, please click the Rate Volunteer bar below and enter a rating and nomination for me. I am a volunteer on this site so Ratings are the only compensation I receive for answering plant questions.

Need more information? Visit my website at:
A link to HorticulturalHelp.com

or email me at [email protected] or call me at 917-887-8601 (EST)
 
Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

Visit my website at: A link to HorticulturalHelp.com