Long time gone

[willowretreat]

Well, I haven't been around for a while.  What's up?  My three year old Stanley Plum looks like it's dying.  All the leaves suddenly drooped and now they're withering and curling up.  What could be wrong?  We've had bouts of intense heat, followed by short monsoon rains, then more intense heat.  Also, do young plum trees need full sun? Because there's a big-ass alder growing up inside the middle of the lilac bush and it's blocking the sun from the plum sapling.  I can't think of anything else that could be wrong.

Any clues?

Thanks!