Swallows don't return, purple flowers soak the moon, and the north blooms and the south withers. What do you mean?

It seems to describe the four seasons in a place.

Swallows don't come back: Spring is late, and swallows haven't come back from the warm south.

Wei Zi soaked in moonlight: Wei Zihua's flowering period is from June to September. This sentence represents July in the order of flowers and months. It is midsummer, and Wei Zihua under the moon is particularly delicate and charming.

Flowers bloom in the north: it begins to snow in autumn in the north and around late September in the northeast. The flowers here refer to snowflakes.

Flowers wither in the south: the climate in the south is warm. In winter, most flowers begin to wither and stop flowering.