What is the meaning of the poem that the puffer fish is coming up?

"When the reed buds are short, it is time for the puffer fish to go up" should mean "When the reed buds are short on the ground, it is time for the puffer fish to go up", which means "The beach is covered with Artemisia, asparagus has begun to sprout, and the puffer fish is about to swim back to the river from the sea", from "Two Night Scenes of Hui Chong Riverside, Part One".

The whole poem is:

Two or three peach blossoms outside the bamboo forest and ducks in the water first noticed the warm spring. The beach is covered with wormwood, asparagus is beginning to sprout, and puffer fish are preparing to swim upstream from the sea back to the river.

The poem Two Nights by the Riverside in Hui Chong (Part I) not only retains the image beauty of the picture, but also gives full play to the advantages of the poem. With its rich charm and mixed pen and ink, the poet makes the spring scenery depicted in the original painting so charming.