Question
Hi, We have 3 honey locust trees in our backyard in New Haven County CT.  I estimate them to be slightly older than our home so over 20-25 years old.  Last spring we had an aphid problem which initially stunted the leaf generation and I was able to solve with some ladybugs help.  This year due to the cool wet weather in the spring and early summer we had fantastic foliage, an overabundance of leaves, probably double over 2008.  However, as soon as the weather became hot about 4/5 weeks ago I would say 50 % of the leaves have turned yellow and fallen off.  The lower branches are the worst affected with about 30 % losing all leaves.  Higher in the tree there is more minor leaf loss and the tree is still growing new ones.  There are some smaller dead branches on all three trees and I did see some kind of (fungus?) growing on one tree - a bright yellow/orange almost jelly looking substance oozing out on the bark during the spring. It was on dead branch which I removed. Before the leaves
fall off they turn yellow, then brown and I have noticed some small black spots on them while they are yellow.


Other honey locusts I have seen in our area (they have them where I work ) have not had this leaf loss so I am concerned we have diseased trees and I would hate to lose them.  Any suggestions on the cause and any treatment would be appreciated.
thank you  

Answer
Fran:

The jelly stuff is probably a fungus that is strictly saphrophytic (growing on dead substrate) and not the cause. I also suspect the leaf spots are incidental, not having much of an impact on the overall health. If possible, just rake up leaves before the springtime and discard.

Leaf yellowing (uniformly),followed by browning, then leaf drop is a common reaction to root stress.  This can be multiple things, including water imbalances (too much or not enough). We had lots of water here this spring, then it turned dry quickly with associated hot temperatures.  I am seeing these leaf symptoms now.  I would examine the trunk for evidences of bark damage (e.g. string trimmers or lawnmowers LOVE trees! Avoiding wounds can be very important in the longevity of a tree.  If no damage is visble on the trunk or roots (like any excavation), I'd probably focus on the water thing. Trees can show delayed stress- maybe for one or two seasons back if times got hard for them then.  A good slow trickle from a garden hose for a few hrs at multiple locations under the drip line may be a good thing.  
Also to consider-- contact your local Agricultural county Extension office- many times someone can come out and visit your tree (make a house call!).  They might see something that both of us might overlook.
If you need help locating this office , let me know.  You can also check phone book under state govt. offices.  The Extension system is associated with a Land Grant Univ.in your state.

Hope this helps.

Steve