Andrew Fretwell, 39, and Mark Hall, 40 both signed up for the one-year diploma programme at from Derby College after taking voluntary redundancy from Tesco, graduating with first and second place grades.
Fretwell was named Arboriculture Student of the Year at the college's Peak Awards. "I have always had an interest in trees and had it in my mind that this was something that I would like to do," he said.
Hall addeed: "I must admit that climbing trees is not for the faint hearted and you need to build confidence in the gear and in what you are doing."
Their company, Green Line Tree Services, provides tree and hedge services around Derbyshire.