What is the proper care for a pink dogwood tree?

I planted a pink dogwood in the spring and have fertlized and water all summer. It is very dry in Tennessee in August so I have watered nearly every day but not flooded the tree. In the spring I used a tree spike (following directions carefully) to fertilize and since then I have used about 1 tsp of garden sulfur over a two month period. Though the tree has shown new growth, the leaves turn brown and curl on the end. Help! I love flowering tress and certainly want this one to be as healthy as the others in my gardens.

Thanks for any information.

Ann