Why should seedlings be hardened off before transplanting greenhouse vegetables? Growers need to know
Seedlings must be hardened off before transplanting greenhouse vegetables
(Agricultural Wealth Network) Gradually hardening off seedlings before transplanting greenhouse vegetables can improve the seedlings' resistance to adverse conditions. Hardened seedlings have stronger cold resistance and drought tolerance, and the recovery period after transplanting is shorter.
The specific method is: 7 to 10 days before transplanting, gradually lower the temperature in the seedling-raising site, control water, stop heating, gradually increase ventilation, and gradually remove the covered straw curtains; by 3 to 4 days before transplanting, they should all be removed (finally bringing the temperature in the seedling-raising site close to the conditions of the cultivation site). Keep the daytime temperature at 15°C to 20°C and the nighttime temperature at 5°C to 10°C. Generally, do not water during this period. If individual seedlings in some spots show wilting at noon, only water a little at any time in the wilted spots so the seedlings can recover. Do not water heavily, to prevent excessive humidity from causing leggy growth of the seedlings.
During the hardening-off stage, prevent cold damage to the seedlings. Pay close attention to local weather forecasts regularly. When a cold wave occurs, do a good job of cold protection and insulation at any time, increase light, control water and fertilize reasonably, and also prevent snowmelt and rainwater from seeping into the seedling bed. When uncovering the curtains in the morning, pay attention to changes in the seedlings. If slight cold damage is found in the seedlings, cover a little less straw or straw curtains so that the light in the seedling-raising site is reduced. Never let the temperature in the seedling-raising site rise suddenly. After the seedlings return to normal, remove the straw curtains again.
The specific method is: 7 to 10 days before transplanting, gradually lower the temperature in the seedling-raising site, control water, stop heating, gradually increase ventilation, and gradually remove the covered straw curtains; by 3 to 4 days before transplanting, they should all be removed (finally bringing the temperature in the seedling-raising site close to the conditions of the cultivation site). Keep the daytime temperature at 15°C to 20°C and the nighttime temperature at 5°C to 10°C. Generally, do not water during this period. If individual seedlings in some spots show wilting at noon, only water a little at any time in the wilted spots so the seedlings can recover. Do not water heavily, to prevent excessive humidity from causing leggy growth of the seedlings.
During the hardening-off stage, prevent cold damage to the seedlings. Pay close attention to local weather forecasts regularly. When a cold wave occurs, do a good job of cold protection and insulation at any time, increase light, control water and fertilize reasonably, and also prevent snowmelt and rainwater from seeping into the seedling bed. When uncovering the curtains in the morning, pay attention to changes in the seedlings. If slight cold damage is found in the seedlings, cover a little less straw or straw curtains so that the light in the seedling-raising site is reduced. Never let the temperature in the seedling-raising site rise suddenly. After the seedlings return to normal, remove the straw curtains again.