# Magnolia turning yellow



## JCONN (Jul 22, 2010)

We recently did a large planting and trim job for a customer. She is very happy however out of everything that we planted she called me flipping that the Little girl hybrid magnolia is turning yellow and dropping its leaves. I have not gone to see the tree yet so I don't have any pics, just going by what customer has said. 

I know mags drop leaves to make room for new but according to hear about half of the tree has turned yellow since last week. The tree has been planted for about 1 month. 

Any help would be great thanks


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## pdqdl (Jul 22, 2010)

Check for over-watering.

"Care: Grow in moist, well-drained, preferably acidic to neutral soil in sun or partial shade; magnolias do not tolerate wet feet."

http://www.finegardening.com/plantguide/magnolia-ann-little-girl-hybrid-magnolia.aspx


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## JCONN (Jul 22, 2010)

Thanks I have a feeling this may be a problem.


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## pdqdl (Jul 22, 2010)

By the way: Isn't upstate NY a bit colder than zone 5? That link I posted says they are only good for cold down to zone 5. I would expect some warranty issues next year.


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## JCONN (Jul 23, 2010)

Yes Mags are good to zone 5 were we are is just that. I went to look at the tree today and found the problem is over watering. We have recieved about 2 inches of rain in the past 3 days and she told me that she has been watering it everyday for about an hour just letting the hose run on the base of the tree.

I also took a few of the leaves to the nursery and they said when the leaves are yellow with green veins its usually a sign of over watering due to the excess water changing the pH of the soil.

Thanks again


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## pdqdl (Jul 23, 2010)

Glad to be of service.

Your nursery is not giving you very good information. Normal water does not change pH, except to bring it closer to 7. If the soil is overly acidic or basic, too much water may bring it closer to neutral. Some water sources are acidic, basic, or may even have certain buffering compounds present. Unless tested, you should presume that the water is pH 7. Water normally has very low buffer capacity, so it quickly becomes the pH of whatever soils it is added to.

Yellow leaves with green veins are often associated with mineral deficiencies. The best known and most common is "iron chlorosis", which is caused by a basic pH that makes iron less available to the plant. Pin oaks are notorious for having this problem in limestone soils, when they prefer acidic conditions.

I have never seen a mineral deficiency in a magnolia, so I cannot tell you what they are prone to.


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## John Paul Sanborn (Jul 24, 2010)

pdqdl said:


> Yellow leaves with green veins are often associated with mineral deficiencies. The best known and most common is "iron chlorosis", which is caused by a basic pH that makes iron less available to the plant.



What he said, we have a big problem with that here, being that we draw water from a limestone aquifer. Gravel drive ways and old concrete can raise pH too.

I've seen evergreens that are pH stressed because the snowplows push TB from the drive in piles in the rootzones


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## pdqdl (Jul 24, 2010)

"TB" ?

What is that?


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