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Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

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Saturday - June 11, 2005

From: Milwaukee, WI
Region: Midwest
Topic: Non-Natives, Diseases and Disorders
Title: Smarty Plants on Oleanders
Answered by: Nan Hampton and Joe Marcus

QUESTION:

I have 3 Nerium Oleanders. In the winter they come indoors, and are under grow lights. They are in big pots. We just put them outside on patio, and they don't look good. They still have green tips on some, but all leaves are medium brown/some green and crisp. What can I do to save plants, this is the first time in 3 years I have seen them this bad. Mother use to take care of the plants. Now they are mine and need help. Any suggestions?

ANSWER:

It sounds like you have salt burn. This occurs when mineral salts build up in the soil from fertilizers and from watering. The salts are taken up by the plant and kill the leaf tissue which dries out, browns, and dies. To rid the plant of salts you need to water deeply and slowly to leach out the salts. Let the excess water drain out and water again. You will want to do this periodically, perhaps once a month.

You definitely want the plants inside in the wintertime since the USDA cold hardiness zones for oleanders are Zones 8-10 with an average minimum temperature of10 to 20 degrees Fahrenheit for Zone 8, which extends from around Dallas southward. Wisconsin is in Zones 3 and 4, with an average minimum for Zone 3 of -30 to -40 degrees. You can read more about the history, culture and care of oleanders from the International Oleander Society.

 

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