Question
QUESTION: Hi, Dr. Vann.  Thanks for taking my question.
I have a young Chinese Pistache tree that has some damage on the branches.  We just had a severe storm two weeks ago that produced golf ball sized hail.  I believe the damage to this tree is from the hail, but i want to make sure.  Attached are links to several photos.  All of the damage is on the top of the branches, and it appears to be impact damage as if something hit it.  As you can see from the photos the wounds are already healing and the tree doesn't appear to be affected by it (ie. no signs of disease of insect infestation).  Anyway, would you be able to confirm my conclusions, or is something else going on?  The last two photos are damage on the main trunk and main branch.

http://www.flickr.com/photos/27657351@N07/7313897850/sizes/l/in/photostream/

http://www.flickr.com/photos/27657351@N07/7313897622/sizes/l/in/photostream/

http://www.flickr.com/photos/27657351@N07/7313897346/sizes/l/in/photostream/

http://www.flickr.com/photos/27657351@N07/7313896684/sizes/l/in/photostream/

http://www.flickr.com/photos/27657351@N07/7313896406/sizes/l/in/photostream/

http://www.flickr.com/photos/27657351@N07/7313896132/sizes/l/in/photostream/

http://www.flickr.com/photos/27657351@N07/7313895786/sizes/l/in/photostream/

http://www.flickr.com/photos/27657351@N07/7313895532/sizes/l/in/photostream/

ANSWER: Tim:
These areas are most likely physical injury as you suggested. Textbook hail damage is often seen mostly on one side of the tree.  No mention of leaf damage in your summary.  Leaves are usually shredded to some extent, particulary if the hail is large and extensive.

Watch these wounded areas as they heal.  If you notice the beginnings of a darken discoloration developing above and below this "open" area, suggest pruning out that area.  We have a wound here and many disease organisms can enter this area and initiate infections.  So, you may need to do a bit of "surgery" to remove any diseased wood.  Don't waste your $ on pruning paints either.  Also, the wounds on smaller twigs may compromise their physical strength, making the more likely to snap off in a wind storm.

Regards  

---------- FOLLOW-UP ----------

QUESTION: Thank you for your answer.  There were a few sprigs of leaves that were knocked off the tree and a few that were shredded but nothing extensive.  In fact in the third photo from the top of the list you can see a leaf that is torn in half right above the wounded limb when the hail stone tore through the leaf on its way to impacting with the branch.  
As I mentioned earlier there is a large wound on the trunk.  If I see dark discoloration around this wound, is there anything you know of that I would be able to do to save the tree?  Hopefully, this doesn't happen, but you never know.

ANSWER: Tim:
Seeing shredded leaves on the tree and on the ground helps to nail the lid shut on the coffin as far as a definitive diagnosis of hail injury.

If possible , can you send a photo of the wound on the trunk? And it dimensions.  This will give me an idea of the magnitude.

Steve

---------- FOLLOW-UP ----------

QUESTION: Below is that photo you wanted.  I had my daughter hold a quarter next to it so you get an idea of the size in comparison to the trunk.  The wound on the trunk is approximately eight inches above the place where the main branch grows out of it.  This is a 1 1/2 year old sapling, so maybe it will recover with no problems.  But let me know what you think.

http://www.flickr.com/photos/27657351@N07/7317194116/sizes/l/in/photostream/

Answer
Thanks Tim for the photo.  As before, just watch these areas for any developing discoloration, then prune out as needed.  In the meantime be sure that the tree is fertilized and watered (especially during hot/dry periods) and be sure to keep lawnmowers and stringtrimmers away from that trunk- these things are often death sentences for our wood ornamentals and trees.

Enjoy.

Steve