Just a FYI note: trees/shrubs need to have their root flare above the grade level when planted. Yours may be planted too deep?

where are you. big city name...

how about some facts for us to work with besides brown l3aves and hot ...

when planted .... how planted.. diy ... how did you water.. does your soil perc.. drain.. etc.. give us some facts to work with ...

pull back the soil until we can see the root flare ... https://duckduckgo.com/?t=ffcm&q=root+flare&iax=images&ia=images

it is not uncommon for recent transplants to go dormant early ... especially if not water to perfection during a heat wave or drought .... if the tree had been properly and deeply watered.. i would expect the grass around the mulch to show an indication of that water ... rather than the surrounding droughted grass ... there is another current post that shows such ....

have you tried a scratch test ...

ken

I suspect what you are seeing is a severe reaction to heat and drought stress. When was the tree planted and how is it watered (frequency and duration)? Your geographic location would be helpful to know as well.

How well the tree may recover from this is up for grabs at this point. Depends on how much damage has been done to the vascular tissue. I wouldn't make any decisions until I saw how the tree responded next spring.

Remove the mulch from around the base of the tree, if you can see/smell rotted roots you planted it too deep if so there is no saving it.

The root flare is visible in the pics.