The role that ultimately went to Marsha Mason was originally given to another actress who 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 girlfriend Christie to leave the film as well since he was supposedly too busy working on Shampoo (1975) and on the script of Il paradiso può attendere (1978), which they made several years later.
Donald F. Muhich, who plays the analyst in this film, was the real-life psychoanalyst of director Paul Mazursky, and also played an analyst in his 1969 film Bob & Carol & Ted & Alice (1969). Filmmaker Paul Mazursky frequently cast his real life analyst, Donald F. Muhich, in his movies. Muhich played a psychiatrist in 'Bob & Carol & Ted & Alice' (1969), an analyst in 'Blume in Love' (1973), a psychiatrist in 'Willie & Phil' (1980), and Dr. Von Zimmer in 'Down and Out in Beverly Hills' (1986).
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).
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.