Frost leaves are red in February, which means maple leaves. "Stop and sit in the late maple forest, and the frost leaves are red in February" comes from Du Mu's "Mountain Walk" in the Tang Dynasty. The maple forest in the poem refers to the maple forest. Liquidambar formosana is a very famous autumn red leaf tree species in China. Its leaves turn red after the autumn frost, and the forest is completely dyed and dazzling, so it is often called "Feng Dan".

This poem comes from Du Mu's Mountain Walk, and the frost leaves refer to maple leaves. In late autumn, there are several families in the place where the white clouds were born along the sloping road paved with stones in the distance. I stopped the carriage because I like the late autumn scenery in Fenglin. The maple leaves after first frost in late autumn are redder than the spring flowers in February.

The poem "Out of the Mountain" describes a trip to a distant mountain, and the specific creation time is difficult to confirm. The author climbed the mountain in late autumn to enjoy the scenery and was intoxicated by this picturesque scenery, so he wrote this poem to commemorate it.

Maple leaves are red in autumn, which is between September and 10. Depending on the region, the temperature is different in different regions, so the maple leaves turn red at different times. If it is in the warm area of the south, the time when the maple leaves turn red will be pushed back, and it may have to wait until 10. The overall ornamental value of maple leaves will be higher after they turn red, and the leaves will fall off soon after they turn red.

After autumn, trees begin to shed their leaves. Before defoliation, trees no longer produce chlorophyll as much as in spring and summer, and the existing pigments will gradually decompose. With the gradual decrease of chlorophyll content, the colors of other pigments will gradually appear on the leaves, so the leaves will show yellow, red and other colors.