Hahahaha. I did. Seemed dry about five inches down. After three days watering, it could still use some tonight.

No change in leaves curling, before or after.

"After three days watering, it could still use some tonight."

Perhaps you are not soaking the rootball thoroughly? It can be incredibly difficult to get water to penetrate a rootball- you need a very slow trickle for a very long time and move the hose occasionally.

How long has the tree been in place? Did you open up the rootball when it was planted and take a good look at the roots? Is it planted too deeply?It looks weedy underneath there- is the tree mulched at all?

Tree was mulched, but the weeds are nuts this year. More mulch needed.

Tree in place since November 2015. We roughed the roots up when we planted it with root crown above ground. I'll poke in a chopstick in a few places so water can get down there.

I agree with cearbhaill. A very slow drip watering might be a order. Maybe that would give you the penetration you need to get down to the bottom of the rootball. I usually try to turn the hose on the the very slowest setting I can and let the water run for at least 30 minutes. That seems to penetrate pretty deep in our clay loom soil. Naturally based on your soil type, your mileage may vary.

I was reading some scientific articles on line, and it might be potassium deficiency. Happens to sugar maples back East, and the first sign is dark green foliage curling. I'll visit the county extension office next week to get the soil tested.