The 24 Oct 1960 DV announced that producer Frederick Brisson and Columbia Pictures would collaborate on a screen adaptation of Lawrence Roman’s upcoming play, Under the Yum Yum Tree, scheduled to open on Broadway on 16 Nov 1960. Roman was enlisted to adapt his own work, and, in early 1962, Richard Quine was brought on to direct, as noted in the 19 Jan 1962 DV, which listed Richard Quine Productions as co-producer. Shortly after, the 7 Feb 1962 DV reported that Frederick Brisson was negotiating a clause in his deal with Columbia, to ensure the title would not be changed from Under the Yum Yum Tree. Brisson had previously disagreed with Columbia over the title of another play adaptation, Five Finger Exercise (1962, see entry), which had been briefly re-titled before reverting to the original.
       Jack Lemmon, who was cast as “Hogan” in the film, had originally been sought to star in the play, as Lawrence Roman had written the role with him in mind; however, due to scheduling conflicts, Gig Young was cast instead of Lemmon for the stage version, as noted in the 16 Apr 1963 LAT. Dean Jones was ultimately the only actor to reprise his role from the Broadway production. Ann-Margret and James Darren were sought to co-star, according to items in the 17 May 1962 and 21 Sep 1962 DV. Later, the 6 Nov 1962 DV stated that Columbia had made an offer to actress Natalie Wood, and the 4 Jan 1963 DV noted that Priscilla Boyd was being tested for a role.
       David Swift was brought on as co-writer and director after Richard Quine’s departure from the film, as announced in a 20 Mar 1963 DV brief. With Roman, Swift revised the screenplay, which veered from the original play in its setting (University of California Los Angeles [UCLA], instead of San Francisco, CA) and by adding the characters “Charles,” “Murphy,” and “Dorkus,” played by Imogene Coca. Swift had originally intended for Coca to appear as “Grindl,” her role in Swift’s upcoming television show, Grindl (NBC, 15 Sep 1963—13 Sep 1964). The 3 Mar 1963 LAT described Swift’s plan to incorporate Grindl into the film as “probably the first time” a movie would debut as a “direct tie-in with an existing television show.”
       A production chart in the 29 Mar 1963 DV noted that principal photography began on 18 Mar 1963. Production was based in Los Angeles, as indicated in the 16 Apr 1963 LAT.
       When the film’s first round of advertisements were released, Jack Lemmon objected to their “debatable taste,” as stated in the 25 Oct 1963 DV. As a result, new copy was created for both newspaper and television ads. The racy subject matter of the film was also addressed in a 13 Oct 1963 LAT article by Philip K. Scheuer titled “The Movies and Sex: How Far, Hollywood?” Scheuer described the theme of Under the Yum Yum Tree as “decidedly unsavory” and Lemmon’s character as “a completely unprincipled lecher and Peeping Tom.” Following mixed reviews, a 28 Nov 1963 LAT item, also by Scheuer, noted that, despite American audiences’ purported “anti-sex-in-films attitudes,” a recent poll of moviegoers found they were generally more interested in seeing Under the Yum Yum Tree than other current releases.
       Bill Bixby, Kathy West, and Joe Palma were named as cast members in DV items published between Mar and Apr 1963, and a man named Otis Greene worked on the picture “in a production capacity,” according to the 15 Jul 1963 DV.