We planted a 5 ft apple tree late winter. The leaves were late appearing , and are still curled. They never fully opened.
Apple Tree Problem
Your young tree was probably injured by the severe winter. Here's an article on encouraging leafing: https://www.gardeningknowhow.com/ornamental/trees/tgen/tree-leafing-problems.htm
and one on general care of apple trees.: https://www.gardeningknowhow.com/edible/fruits/apples/apple-tree-planting.htm