Blum married Henrietta Cecilia Smit (born 3 November 1911, died 2002 in Worthing, Sussex, UK), a South African art teacher, in 1955.

His success as a poet was first affirmed in 1956 when he won the Reina Prinsen Geerligs Prize for his volume Steenbok tot poolsee (the title being a reference to the Tropic of Capricorn and the southern Antarctic Ocean, relating to the geographical location of South and Southern Africa).

Kannemeyer (1993) speculates that citizenship was denied because of Blum's vociferous opposition to the ruling National Party's policy of apartheid.

Frustrated by this turn of events, Blum and his wife left South Africa to resettle in the suburb of Hounslow in London.

Inspired by François Villon's Ballade des Dames du Temps Jadis, Breytenbach compared Afrikaner dissidents Peter Blum, Ingrid Jonker, and himself to unfaithful lovers, who had betrayed Afrikaans poetry by taking leave of it.