Cotton grows in summer.

This is a passage from 24 solar term song:

Planting cotton should be finished before the valley comes. In dog days, that is, when the weather is hottest, you should always hoe the soil to take care of it. Sugarcane should be planted in Grain Rain, and cotton should be planted in the long summer. If the sowing time of wheat is delayed, it will not germinate, and if rape matures too late, there will be less oil. The days around Tomb-Sweeping Day are suitable for planting melons and beans.