Question
Sir,

We have a sunset maple that we planted two years ago.  Last year it lost most of it's leaves early and never looked well.  This year it was looking ok and then we had a late snow (in JUNE!) and it got nipped.  Part of the tree's leaves are dark green and then part are starting to look a little yellow.  It's leaves are pretty sparse.  
We just got a sprinler system this year.  We don't know if we're over watering, underwatering, need to expose the crown more.  It's in an island and has mulch around it, but not touching the tree itself.

HELP!!
Trouble in Wyoming


Answer
If you dig under the mulch and the soil is wet (has water in it if you squeeze the soil in your hand) it is getting too much water. If the soil is dry too little. It should be moist. But with part of the tree green and part light green I would say it does not sound like a water issue. You might try adding some fertilizer around the tree--use 10-10-10 fertilizer at the rate of about a cup per inch of trunk diameter scattered around the tree and watered in. Fertilize just before a rain storm and you will not have to water. Also make sure that you do not use a fertilizer for the lawn that contains a herbicide for weeds. These come in various names like Weed and Feed. The herbicide in these will damage or kill tree roots. Liquid herbicide for lawns is fine but the granular ones will effect the tree. Other than that from your description I am not sure what the problem could be with out seeing the tree.