I know that Al Campbell has a song named “Grass is Green”. But as a young boy growing up my mum used to play the same song just by a different reggae artist. It had slightly different lyrics. For example, in Al Campbell’s version, he says when the grass is green I’m “Happy”. In the one, my mum had the singer said when the grass is green I’m “lonely”
Anything in the lyrics about having to knock on wood?