Why did my maple die so suddenly?

Every day I receive calls about plant problems.  It is often very, difficult for me to determine what the problem may be over the phone.  So, I ask for plant samples or pictures, depending on the description of the problem.

In this case, this maple died very suddenly.  This does not sound like a disease or insect problem to me.  Yes, maples can have problems with Verticillium wilt, but let's not be too quick to blame this disease.  Further investigation should be done.   First of all, the drought and heat this summer have been very, harsh on tree health.  Unfortunately, if that tree has any preexisting decline problems, this stressful weather will not help! 

I usually ask for a picture of the tree base.  Here I can see that this tree is suspect for being planted to deeply.  It is hard for someone to believe, but yes, a tree can survive for many years being planted to deeply; however, when harsh growing or site conditions arrive, the tree can quickly decline.  It is also possible that this tree could have had a girdling root on it's left side.  Deep planting and girdling roots can cause the tree to decline.  But, could the hot/dry weather and incorrect planting cause the tree to die suddenly?

If a root rot or wood decay fungus infects the declining tree.....yes, that can cause a sudden death. The symptoms of the maple in the above pictures are very symptomatic of Armillaria root rot. For more info, you can check out this link: http://www.na.fs.fed.us/spfo/pubs/fidls/armillaria/armillaria.htm

There are some species of this fungi that are just saprophytic (survive on dead wood), but there are some that can be parasitic (cause disease). I can’t tell you which came first. It is still possible that that the girdling root/deep planting killed the plant and then Armillaria invaded later. But, Armillaria root rot could have caused the tree to die too.