Start of Summer (Chinese: 立夏), the 7th solar term of the year, began this year on May 5 and ended on May 20. On this day, the point on the earth's surface at which the sun's rays are perpendicular to the ground reaches 45 degrees. During the Start of Summer time, all vegetation is in luxuriant growth. It's a crucial time for the harvest of wheat, rape and other summer crops. Meanwhile, the temperatures of North and West China increase quickly during this period of time, but the rainfall is still insufficient. In spring, heavy winds accelerate evaporation from the soil making the dry air and soil unfavorable for the growth of crops. Weeding is every important during this period. It can remove the grass, combat drought and flood, raise the temperature of soil, and accelerate the decomposition of soil nutrients. [Photo by Wan Jin/Palace Museum]