Lignification poor root shallow non-freeze-resistant northern blueberry how to prevent cold and survive the winter

The Lignification degree of blueberry branches is poor and the root system is shallow, so the cold tolerance of blueberry is poor. Blueberries cultivated in open fields in cold areas of the north must be protected against cold. Here are several practical cold protection methods for blueberries.

Blueberries are covered with cold

1. Covering the cold protection method. Before freezing, cover blueberry trees with leaves, straw, straw curtains, woven bags, etc., can play a protective role, before cold should be filled with water. The effect is better in the areas where the lowest temperature in winter is above-15 ℃, and the cover thickness can be 5~8cm. In the areas where the lowest temperature in winter is lower than-15 ℃, the cover thickness can be increased. The blueberries that use this method will still strip in the drier areas in winter, and the effect is not satisfactory.

2. The method of preventing cold by making snow. Artificial snow can be made in snowy areas. Because of the convenience of collecting materials, it has the advantages of labor-saving, time-saving, low cost, maintaining soil moisture and so on. Generally, the suitable mulch thickness is 2cm 3, and the suitable thickness is l5~30cm. The effect of making snow against cold is good, there are few strips, and the yield is also increased, but this method is limited by the region, and can not be used in areas with little or no snow.

3. The method of cultivating soil to protect against cold. In the northeast of China, the method of cultivating soil and keeping cold can be used in blueberry cultivation. Before the beginning of winter, crush the branches and cover them with soil. The effect of cultivating soil against cold is good, the strip is very light, and the growth result is good. However, blueberry branches are brittle and easy to break, so orchards with buried soil to protect against cold should be oblique or used in the young tree stage. When the tree grows up, the amount of soil will increase, coupled with the removal of soil in spring, not only labor-consuming, time-consuming, increased investment, but also great damage to the tree, often resulting in breaking branches and damaging flower buds, affecting growth and fruit.

4. The method of double-layer covering against cold. The cold protection method of straw curtain and plastic film is suitable for more than 3-year-old blueberry garden. Before preventing the cold, take blueberry planting line as standard, slightly higher than blueberry, set up a horizontal sorghum, you can use wood pole, bamboo pole or iron pipe. On the set-up beam, cover the plastic film, the width of the plastic film is grounded on both sides and can hold the soil as standard, after pressing the soil on both sides, cover the straw curtain, the straw curtain should be covered strictly, can not expose the plastic film, and then fix it with pulling wire or clamping wire to prevent the strong wind from blowing away. The double-layer covering uses more cold-proof materials, but it is labor-saving when it is cold-proof, and the materials can be reused for 3-4 years. The important thing is that the cold-proof effect is good. In the area where the lowest temperature in winter is not lower than-25 ℃, there is almost no frost injury and striping, strong tree growth, good blueberry quality and high yield. The use of double-layer covering cold protection method should pay attention to several points: the cold protection time should be timely, not too early, it is appropriate to stabilize the external maximum temperature below 5 ℃, too early will make the bud hot (commonly known as covering the bud); before cold protection, when the soil moisture is not good, it needs to be irrigated once; the cold proof material should be removed in time in the next spring.