No idea where you are but in the south east there is a blight that kills all young dogwoods (doesn’t hurt established ones) so we can no longer plant them. It’s been a problem for thirty years. If you want white flowers on a small tree a Natchez white crepe myrtle might scratch the itch.

Where are you located? How much sun does the tree receive (morning or afternoon)? Describe your watering routine.

I a in central Ohio, zone 6. I have scaled back on watering, except a couple of really hot & dry weeks we had in early June. Since then, we have had what seemed like enough rain to not require watering. The tree gets 6 hours of sun, which is morning + early afternoon. Here is a pic taken yesterday.

Could be the start of powdery mildew on the leaves, tho that doesn't usually (at least quickly) kill the leaves.

Please put a gator bag on it and take the guess work out of watering.

How was it planted? What did the roots look like? Was it potted or balled and burlaped? Why is the shipping stake still attached?

tj