Onions should be supplied with sufficient water during the germination period, seedling growth period and bulb expansion period. However, during the seedling period and before overwintering, water should be controlled to prevent the seedlings from growing excessively and suffering from freezing damage. Control irrigation 12 weeks before harvest to make the bulb tissue full, accelerate maturity, and prevent bulb cracking. Onion leaves are drought-tolerant and suitable for humidity of 60% to 70%. If the air humidity is too high, it is prone to disease.
