Question
I have a three year old southern magnolia tree.I live in Devine Tx
I have never had any problems until about a week ago. Almost over night almost all of the leaves turned brown. There are just a few green leaves left. We have watered it regularly, it is just heat stress? I would not like to think that it is going to die. Can you help?

Answer
Dawn:
Magnolia is a hardy tree.  If the leaves changed overnight, I would probably be suspicious of something rather than an infectious type of disease- maybe something stressful happened in the its environment.  Take a close look at the base of the tree near the soil line for any evidence of bark damage.  If there is some injury present- this could be an issue. String trimmers and lawnmowers love to damage trees- and this is almost always a death sentence. This is irreversible.

Some parts of TX have been very dry over the last few months.  Not sure how regular you have watered, but the soil needs to be moist, not overly dry or wet. The soil needs to drain good as well. You might be able to take a small shovel and examine the soil down to about 1-2 ft to see if it is too dry or wet.  If the tree has gone through an extended period of hot/dry conditions, it may take a while before the tree starts to show.  You can try scratching those twigs with brown leaves with your fingernail, looking for green tissue beneath the bark.  If green is present, then tree may be able to re-leaf, assuming the stress is corrected.

Steve