What does it mean that the Ming Dynasty knows Grain Rain, and there is no policy of banning flowers?

I know it will be Grain Rain tomorrow, but there is no good way to stop the wind from blowing off the petals.

This poem is from Grain Rain written by Zhu Yun in Song Dynasty.

Full text:

The sky is in the forest and the dream is written on the eaves.

Knowing Grain Rain in the Ming Dynasty, there is no way to ban flowers.

Zhu Shi's technique is ingenious, but the smoke is faint.

The more you are locked in a poultry prison, the more I say to God.

Extended data:

Climatic characteristics

The main feature of the weather in Grain Rain is rainy, which is beneficial to grain growth.

After the solar term in Grain Rain, the rainfall increased and the humidity in the air gradually increased. At this time, we should follow the changes of natural solar terms and take care of the climate characteristics. With sufficient and timely rainfall, cereal crops can thrive.

Low-altitude valley areas are used to enter summer. The climate characteristics of high temperature in south China in spring are beneficial to the early cropping cultivation measures in Da Chun. The experience in the old arid areas in southern China has proved that planting Osmunda japonica early in Grain Rain can seal vine leaves before summer drought, enhance drought resistance and achieve high and stable yield.

Baidu Encyclopedia-Grain Rain