In what year did Hermann Kasack publish his first poem?

There is no reliable information available about Hermann Kasack publishing a poem in any year. Hermann Kasack was primarily known for his novels, not poetry.

He is best known for his novels like "The City Beyond the River" (1948) and "The Children of the Sea" (1950), which explored themes of the individual in society and the power of the past.

It's possible that he wrote poetry, but there is no evidence of it being published.