1、 How to judge

You can first break down the branches of the tree to see if there is still water and color in the cross section. If there is more water, the color inside is relatively bright, which proves that there is no problem with the plant. If the inside of the branch is dry, you can also carve a line on the trunk to see if the surface has become dry brown. If it is still green, it proves that it can be saved. If the degree of dry brown is deep, don't easily judge whether it is dead. You can observe the root system. If the degree of decay is not serious and there is vitality, it proves that it can survive. If the decay inside is serious, it has been dry, It means he's dead

2、 Precautions

This kind of rotten root is generally caused by excessive watering, or it is not watered thoroughly at ordinary times, so it is difficult for the root system to breathe inside, resulting in decay. Some non dead can be saved. First cut off the rotten roots, and then replace them with basin soil for maintenance. The upper part should also be treated and the dead branches should be removed, which can promote the germination of hidden buds and grow new branches and leaves again