The role which ultimately went to Marsha Mason was originally given to another actress that was going to shoot another film. She called to ask the director, who declined, to push production of the film back for a couple of months. Mazursky hung up the phone and contacted his casting director, asking about Mason who just so happened to be at the casting office. When the actress walked in, the director hired her on the spot.
Warren Beatty and Julie Christie had been previously offered to play Stephen and Nina Blume, when this project was in development and, for a while, they were both attached, until Beatty dropped out, convincing also then-lover and partner Christie to leave the film as well since he was supposedly too busy working on Shampoo (1975) and on the script of Heaven Can Wait (1978), which was made by them, only several years later.
The title of the movie is a word play on "Love in Bloom" which was a hit song for Bing Crosby in 1934 and which later became Jack Benny's theme song.
At one point Elmo (Kris Kristofferson) waxes nostalgically about Brownsville, Texas as a place he once lived. Kristofferson is, in fact, from Brownsville.
It is this movie that Alice Harford (Nicole Kidman) is watching the opening scenes of on television in Stanley Kubrick's 'Eyes Wide Shut' (1999).