Question
I have a 4-5 year old sweet gum tree in Northeast Ohio.  Lately, the leaves on the inside are turning yellow and dropping. Any ideas?   Thanks in advance!

Answer
Some interior leaf abscission (leaf drop) almost always occurs in mid- to late-Summer as a response to drought, long before normal Autumn leaf drop.  So, if it has been a hot summer, try supplimental watering to slow this down.

Also, leaves tend to respond to higher levels of toxic stuff in The soil - here its lots and lots of boron, but there are all sorts of items that in small quantities the plant needs, and in higher amounts causes stange responses.  It is a cheep thing to have your soil tested - here, its about $35.

Hope it helps!   ~Marc