Detailed Guide to Frost Prevention Methods During the Blooming Period of Sweet Cherry

Irrigation before bud break delays bud break and blooming. Flood irrigation on the ground before bud break can delay sweet cherry bud break and blooming. It can effectively lower soil temperature and avoid frost damage. When the nighttime temperature drops to around 2°C, light the grass piles to ensure the entire orchard is covered in smoke. The smoking time is best continued until the sun comes up the next morning. About 7 days before sweet cherry blooming, cover bamboo poles with plastic film. The plastic film should only cover above the cherry orchard to ensure ventilation. Remove the film about 2 weeks after fruit set.

There are two types of frost damage to sweet cherry. The first is early frost damage, which occurs relatively early, mostly during the dormant period around the Spring Festival, and is mainly caused by extreme low temperatures, resulting in flower bud damage or dead trees. The second is late frost damage, which mostly occurs after sweet cherry bud break until the young fruit stage, and is caused by a sudden temperature drop after warming or by frost, resulting in damaged flowers or young fruit. Early frost damage is closely related to the later management of sweet cherry and tree nutrition. With fine management and good tree nutrition, frost damage is lighter; otherwise it is heavier. Late frost damage is closely related to the site conditions of sweet cherry. It is likely to occur in cold depressions and low-lying areas, while it is less likely to occur on well-ventilated mountain or slope land.

How to prevent frost during the blooming period of sweet cherry

(1) Irrigation before bud break delays bud break and blooming. Flood irrigation on the ground before bud break can delay sweet cherry bud break and blooming, causing sweet cherry trees to bud break 3-5 days later. It is best to irrigate with well water, which can more effectively lower soil temperature, delay bud break and blooming, and avoid frost damage.

(2) Smoking to prevent frost. According to the local weather forecast, on nights when frost is coming, pile crop straw or wheat bran grass piles at certain intervals in the sweet cherry orchard in advance. When the nighttime temperature drops to around 2°C, light the grass piles to ensure the entire orchard is covered in smoke. The smoking time is best continued until the sun comes up the next morning.

(3) Set up frost prevention greenhouses. In early spring, bury 1 stone pillar at intervals of about 4 m between sweet cherry rows, with the top of the stone pillar 20-30 cm above the sweet cherry trees. Use bamboo poles as crossbeams between the stone pillars and fix them with ropes. About 7 days before sweet cherry blooming, cover the bamboo poles with plastic film and tighten it with ropes around the edges to prevent it from being blown away by wind, with 2 rows as 1 structural unit or the whole orchard connected as one. Do not cover the surroundings with plastic film; only cover above the cherry orchard to ensure ventilation. Remove the film about 2 weeks after fruit set.