Detailed Explanation of Hardening-Off Methods and Precautions for Early Spring Vegetables
Although the epidemic situation is severe, the vegetable basket still cannot be cut off. Now many early spring vegetables have already begun to be planted one after another, but during hardening off, seedlings are very likely to suffer cold damage and disease damage after planting. So how should early spring vegetables be hardened off? What should be noted during hardening off? Follow the editor to learn about it together.
1. Hardening-off time
The hardening-off time is generally controlled at about one week, usually carried out 7-10 days before planting. In the first 5-7 days, temperature control, water control, and appropriate ventilation are generally carried out. In the last 3-4 days, continue cooling, water control, and full ventilation to promote the seedlings to fully adapt to the environment after transplanting. Cooling should be carried out gradually, water control should also be appropriate, and ventilation should go from small to large. In addition, the low-temperature hardening-off time should be neither too long nor too short. If the hardening-off time is too short, it cannot play the role of strengthening seedlings and healthy plants. But if the hardening-off time is too long, it is very easy to form aged seedlings, which is not conducive to seedling recovery and is also very prone to premature aging, which is extremely unfavorable to later growth.
2. Hardening-off methods
10 days before planting, gradually lower the temperature of the seedbed. During the day, appropriately increase the ventilation amount and extend the ventilation time. In the evening, cover the shed appropriately later and leave an appropriate amount of gaps for slow cooling. The daytime temperature can be slightly higher, while the nighttime temperature can be as low as about 12 degrees. Under the condition of ensuring that the seedlings are not frozen, reduce the nighttime temperature as much as possible. During low-temperature hardening off, seedlings grow slowly, so water should be appropriately controlled. Also, before hardening off, potassium dihydrogen phosphate can be sprayed to improve the stress resistance of the seedlings. During hardening off in autumn, as long as the seedlings do not wilt at noon, watering is generally not needed. If there is wilting, a small amount of water can be appropriately applied or water can be sprayed so that the seedlings only need to recover normal growth.
3. Precautions for hardening off
During hardening off, always pay attention to the weather forecast. When cooling and cold waves occur, appropriately cover the seedling shed in advance at night in time to prevent the seedlings from freezing damage. During hardening off, the low temperature should be reasonable. If the temperature is too low, it will cause problems such as the seedlings turning yellow again, thin stems, and stiff seedlings. During hardening off, promptly remove those diseased, weak, and incompletely developed seedlings, appropriately increase the spacing between seedlings, and increase air permeability. After planting and seedling recovery, appropriately widen the day-night temperature difference for seedling hardening. In this way, the seedlings can be promoted to become stronger further.
The above is an introduction to the hardening-off methods and precautions for early spring vegetables. I hope it can help you. If you want to learn more related knowledge, please follow us.