1 bud:
Because of the weak cold resistance of plant flower buds, early spring occurs more often, especially the top flower buds, which is the key period to strengthen anti-freezing maintenance.
2 branches:
After the branches of plants are browned by frostbite, the branches growing from the browned parts gradually dry up and die, and the epidermis cracks and browns, but if the cambium is not frozen, it can be restored. In particular, immature top branches are sensitive to cold, and often freeze injury occurs first, and the pulp changes color in light cases, and the branches in heavy cases are dehydrated, shriveled and even frozen to death.
3 backbone:
After the plant trunk is frozen, it will form "frost crack" and the bark will fall off in pieces. It is necessary to take timely measures to paint the trunk white, wrap the trunk or other anti-freezing and cold-resistant measures.
4 necks and roots:
After the root neck of plants is frozen, the epidermis first becomes discolored and dry, and the cracking of cortex is harmful to plants. The cold tolerance of root system is worse than that of aboveground part. After root system is frozen, cortex and xylem are separated.
5 leaves:
Generally, plants with large and thin leaves are easy to freeze, while plants with small leaves and thick waxy layer have slightly stronger frost resistance. Young leaves with high water content are easy to freeze, the middle and outer leaves of the whole crown are easier to freeze than the inner leaves, and the tuyere leaves are easier to freeze than the leeward leaves. Generally, in tree maintenance, measures such as pruning and shaping or spraying antifreeze can be taken before the arrival of low temperature.