How do I know if tree is dead

Question

I bought a willow cherry tree in April. It’s about 45″ tall. Today, it lost all of its leaves, dried out even though I watered it. Ends are dry. I scratched the bottom trunk, and it is brown.
How do you know if it’s time to say it’s dead?

Answer 1

Here is an article on how to identify a dying tree that may help you:
https://www.gardeningknowhow.com/ornamental/trees/tgen/what-does-a-dying-tree-look-like-signs-that-a-tree-is-dying.htm

Given that this is a new planting and you had a scratch test that was 'brown' I would approach the nursery you bought this tree from and inquire about a replacement.