What is the explanation method of planting melon beans before and after Grain Rain?

Because during this period, the weather began to get warmer and the soil temperature increased. "Planting melons and beans before and after Grain Rain" is a planting method in China's traditional farming experience. It means that among the 24 solar terms in China lunar calendar, Grain Rain solar terms are suitable for sowing melon crops. The specific explanation is as follows: Before the Grain Rain solar term in Chinese lunar calendar (usually around April 19), the weather began to get warmer and the soil temperature increased during this period, which was beneficial to the growth of melon crops. Such as watermelon, cucumber, pumpkin and so on. This period can be planted; Grain Rain ordered beans later: after the Grain Rain solar term in China lunar calendar (usually around May 6th), because the soil was moist and the temperature was suitable during this period, which was beneficial to the germination and growth of bean crops. For example, soybeans, edamame and green beans can all be sown during this period.