For the scene in which Spock plays his Vulcan harp for Adam (the last time he plays the instrument on the series), the background music for Uhura's song from Charlie X (1966) is recycled.
The space hippie protest "Herbert, Herbert, Herbert!" is a gag, referring to both Star Trek four time director Herb Wallerstein, and long time Executive in Charge of Production Herbert F. Solow. (Spock tells Kirk that the reference to Herbert is "somewhat uncomplimentary" and that "Herbert was a minor official, notorious for his rigid and limited patterns of thought.")
Uhura does not appear in this episode. Lieutenant Palmer, who fills in, makes her second and final TOS appearance after The Doomsday Machine (1967).
Walter Koenig was highly critical of the writing for "The Way to Eden". In particular he felt Chekov was written as too authoritative, rigid and by the book, a complete contrast from his usual and intended characterization.