I am looking for a young adult book, probably written in the late 60's to mid 70's, it was a dystopian future where people seemed to be set in for specific roles. The main character, a boy, wanted to be a farmer or gardener, while society was dictating he should be something else. There was something about a food shortage, or control of food, such that him being a farmer or gardener was somehow forbidden. I can't really recall more than that. Mostly the story was about how the boy learned secretly how to raise plants and with another (perhaps a girl) escaped the place he lived.
I know not much to go on, but it's one I recall liking when I was young but can't remember more of the story.