Question
my pecan tree is around 40 to 50 years old.very very big.it lives about 50 feet from a creek.My wife and i can barely get our arms around it.It just started losing a large section of bark,starting about 25 feet up and coming down 10 feet and 1 to 1 1/2 wide areas.we 1st noticed after a hail storm and thought it was the storm.But since it has started an other area on the other side.Big pieces of bark.Looks dark colored where the bark fell off.Any ideas?   Thanks    Jesse

Answer
If there is new bark under where the bark is being sloughed off then this is normal. As the pecan tree grows in size with age, the oldest bark changes from smooth to scaly and the scaly outer bark splits and sloughs off over time (leaving more scaly bark underneath). Usually, the pieces that slough off are not large, a few inches long by an inch or so wide and less than a quarter inch thick and are rarely even noticed by people who have had pecan trees for many years and are familiar with the fact that mature pecan tree bark is scaly rather than smooth.
Sometimes ants will make their nest under the bark and cause the bark to drop but in this case you would see the ants. From what you are saying if the leaf color is green and the branches are not dying it sounds like this is normal bark of a old pecan. The hail would knock the bark off and speed up the natural bark shedding.