Answer and explanation:
The expression "young man peach tree switchings" belongs to the following excerpt of the story "Where the Red Fern Grows":
Then something bad happened. I caught one of Mama's prize hens. I got one of those "young man peach tree" switchings over that.
The narrator-character is a young boy, Billy. He is setting up traps to catch rats, but sometimes ends up catching something else. His mother is already upset about the cat getting caught several times but, when Billy catches one of her hens, she gets furious. A switching is a rod or a twig that is strong and flexible, and is used for spanking. Thus, when Billy says he got some "young man peach tree" switchings, he means he was spanked as a punishment for catching the hen.
