Question I have a Weeping Willow that is about 10 years old. There is red stuff growing all over it, and the bark is splinting all over. Can you tell me what is all that red stuff is?
Answer HI Joni, I searched and found this answer for you. If the growth is on the trunk or bark area then it is either a lichen or the fruiting body of a decay fungus. If it is a fungi then under the growth should be soft. If it is then the wood inside the tree may have decay fungus--but it should not cause the tree any problems except that it will become hollow in 10-20 years and then the trunk can lose some of its strength and possibly break in a wind storm.
I lean toward a lichen--the bark and wood under the lichen in solid not mushy. The lichen is growing on the bark surface and it will not harm the tree. Usually lichens are grey green in color but during the time they "flower' they can become quite colorful.
In any case if the foliage is green and healthy looking then there is no concern for the health of the tree. And there is no treatment needed for any of these above problems." kathy