I planted a few trees in my back yard, and I noticed that the gas tree developed, grew, and needed water and pets much, much quicker than the other kinds of trees, so it looks like something's a bit off there. :)
I looked into this and didn't see anything, so for now I'm going to chalk this up to randomness. If you continue to see this, though, could you update this thread and let me know, and I'll take a look at the tree in your back yard specifically, etc.?