What is onion in the first month? Do you mean shallots? Or green onions?

As the saying goes, "onions in the first month, leeks in February"

Onions in the first month means eating onions in the first month and eating onions in the first month. Spring onions or shallots growing in the month are cultivated in southern China and Zhangqiu, Shandong Province. Onions planted in the first month of the lunar calendar are the most nutritious, tender, fragrant and delicious.