What does it mean that some trees are red for a long time and people say they are kapok?

It means: Looking around, the rows of tall trees nearby cannot block the red sky at all. I look at the white clouds like kapok, which is particularly attractive. Attention.

This sentence comes from the ancient poem "Chao Hui Daozhong", written by Liu Kezhuang, a poet from the Song Dynasty.

"Chao Hui Dao Zhong"

In the depth of spring, you will never see beautiful flowers, but as far as the eye can see, the yellow grass is surrounded by white sand.

A few trees have been red for a long time, and people think they are kapok flowers.

Translation: Spring is approaching, but I can’t see any spring in the depths of nature. Looking into the distance, there is only boundless yellow sand and white land. Looking around, the rows of tall trees nearby could not block the red sky at all. I looked at the white clouds, which were like kapok, which was particularly eye-catching.

About the author:

Liu Kezhuang (September 3, 1187 - March 3, 1269), originally named Zhuo, courtesy name Qianfu, Haohou Village, Putian City, Fujian Province people. He was a poet, lyricist and poetry critic of the Bold and Unconstrained School of the Southern Song Dynasty.

He was the chief clerk of Jing'an at first, and later traveled to Jiangsu, Zhejiang, Fujian, Guangzhou and other places for a long time. His poems belong to the Jianghu Poetry School. His works are rich in number and broad, talking about current affairs and reflecting people's livelihood. In his early years, he studied the late Tang Dynasty style, and in his later years his poetic style tended to be the Jiangxi Poetry School. The poems were deeply influenced by Xin Qiji, and many of his works were bold and unrestrained, with prominent prose and argumentative tendencies.