I adore Uncle Shelby. He wrote some of my favorite light verse ever and some hilarious songs ('Polly in a Porny with a Pony', anyone?) but I loathe this book with every fiber of my being. It's hideous. Negative twelve billion stars.
I remember reading this story as a child, and feeling both happy for the tree at the end and puzzled about the tree's relationship to the boy. I disliked that selfish boy who seemed to only take and never feel the slightest gratitude for the tree's sacrifices. Re-reading this as an adult, I suppose ...