Seeds were soaked and germinated at the end of March or the beginning of April, and seedlings were raised in the greenhouse using seedling trays and nutrient pots. Seeds soaked in warm water 8h, drain the surface water, wrapped in a wet cloth, placed in 25 ~ 28 ℃ room temperature germination, 1 ~ 2d after the selection of germinating seeds sown in seedling trays, daytime temperature of 25 ~ 30 ℃, the night temperature of 20 ℃ is appropriate. Seedling cotyledon unfolding, transplanted in a nutrient bowl, each bowl of 1 seedling, bowl of nutrient soil for fertile soil and rotting high-quality farmyard manure prepared at a ratio of 1:1. Daytime temperature control at 25 ~ 28 ℃, the night at 12 ~ 15 ℃, pay attention to the control of seedling moisture, to prevent low temperature, high humidity conditions under the occurrence of epidemics or sudden collapse disease, planting should be ventilated 1 week before the refining of seedlings.