das uneindeutige ist das konkrete.
[concrete is what's ambiguous.]
— Franz MonAs late as 1985, but still before he had won the Nobel prize, Günter Grass, who was growing up while the Nazi ban on so-called entartete Kunst (degenerate art) was in force, publicly declared his contempt for abstract art. Already as early as 1960, when he was freshly famous after the appearance of Die Blechtrommel (The Tin Drum) in 1959, Grass had termed the avant-garde poet Franz Mon a “laboratory poet.” That was in a speech on poetry held at a writers' conference held in Berlin. Grass's remark was an allusion to Gottfried Benn, who had spoken favorably in 1954 of a “wordlaboratory.” Grass did not mean to be complimentary when he compared a poem of Franz Mon's with a German children's word game that involved repeating one word, for example Blumenkohl (cauliflower), twenty-five times, until it had lost all meaning.
In spite of Grass's criticisms and, later, those of the proponents of engagierte Literatur (politically committed literature), Concrete Poetry flourished in the sixties in Germany. Some authors, such as Helmut Heißenbüttel and, considerably later, Ernst Jandl, were marketable; so was the Wiener Gruppe (Vienna Group), and concrete poems were widely broadcast on radio.
However, interest in Concrete Poetry declined after about fifteen years. This was not so much a result of hostile opposition from engagierte Literatur (which is itself now out of fashion) as of the failure of audiences to understand.