Because in a year, autumn and winter intersect, the weather is dry, the rainfall is reduced, the tea grows by dew, the young seedlings don't grow in vain, the old leaves thicken, and the leaves are rich in nutrition. So when picking at this time, the tea leaves are particularly sweet and astringent. Therefore, the best picking time is after the first frost.
Frosted mulberry leaves:
Frosted mulberry leaves, that is, mulberry leaves harvested after frost, belong to mulberry leaves of deciduous trees in Moraceae. Traditional Chinese medicine has always believed that frosted mulberry leaves are of good quality and have been recorded in many medical materia medica or classics. It can be seen that mulberry leaves have special requirements for frost harvest.
There are also some folk agricultural proverbs, such as "medicine in season, planting grass in off-season", "planting wormwood in March and April, burning firewood in May and June" and "Anemarrhena asphodeloides is planted in Huangfen all year round, but the quality is higher in spring and autumn".