That’s Clive James in Cultural Amnesia (2007) in the chapter devoted not to Larkin but to Paul Valéry. In fact, Larkin did find a place for the phrase, in the first stanza of “Autumn,” a poem he never published during his lifetime:
“The air deals blows: surely too hard, too often?
No: it is bent on bringing summer down.
Dead leaves desert in thousands, outwards, upwards,
Numerous as birds; but the birds fly away . . .”
In his notes in The Complete Poems (2012), Archie Burnett dates the first draft of the poem to 1953. In a letter to Monica Jones from 1956, Larkin terms it “a flop.” Typically, he jokes about it, saying he aspired to write a version of The Seasons or 4 quartets: “it would be hard to avoid being corny – typing up various ideas with each season, like Ulysses (autumn – dissolution – middle age – resignation – twilight of W. civilization, etc.).” A nice takedown of Modernist pretentiousness.
James sees Larkin’s willingness to stringently wait, to hold himself to high standards that others may not recognize and resist instant gratification, as a mark of his disciplined genius: “He found ways of saying things and the ways led to poems. For all good poets, something like that process happens.”
I’m no poet but I have often put together phrases that pleased me, or even discovered and socked away choice new words, but found no appropriate place to use them. I write down such things or at least try to remember them until the proper hole in a sentence comes along. In 1981 I came upon “fossiliferous,” a delicious adjective that refers to rock, especially limestone, containing fossils. In part because it sounds high-falutin’, I’ve never found it a good home.