Fruit tree leaves

Dear Mike or board members:
I recently planted four trees, two apples (Wolf River and a Gala), and two different peach trees. They were potted trees and I planted them in a mix of bagged composted cow manure and bagged peat moss as I have some pretty sandy soil. I also watered very heavily, and then placed pine wood chip mulch (2 inches) over the root spread and place a mouse/rabbit cage around the tree.

My question is: the edges on those leaves are turning from a healthy, succulent green and are looking dry and turning brown on the edges. I has been raining every other day or so and I was wondering what might be done to stop this browning of the leaves?

G. Rowe in Bad Axe, MI

A signed copy of my book, "Easy Plant Propagation" is a great gift idea!