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Plant Diseases/Black holes/spots on Quercus palustri bark?


Quercus Palustri
Quercus Palustri  

Quercus 2
Quercus 2  
Hello, I wanted to know what is causing the following marks on a normally healthy Quercus palustri. It has had these marks since the moment it was planted, apparently to no effect on the overall health of the tree, since all of its "siblings" planted around it have grown to the same height and width.

But from a group of around 40 tress, it is the only one showing these curious deep formations on what it seems to be a healthy not eroding bark.

Thank you so much for your time. Juan.


I do not know the cause of the holes/fissures in the bark.  I suspect that the tree sustained some sort of physical injury probably at an early age.  These wounds may have been caused by improper handling or other injury.  There is a possibility that these wounds may also be entry points for insects/disease organisms to gain access to the tree interior- leading to internal decay to some level.  Breeches in the bark can be entry points.  An intact bark is important in disease/insect prevention.  If decay is present, this may ultimately weaken the structural integrity of the tree maybe leading to failure, especially during a high wind or winter accumulations of ice/snow.  These areas are surrounded by the greenish patches of lichens.  Lichens are not considered disease organisms, but can be seen on stressed or older declining plants.  Some lichens can even grow on non-living things like rocks, fence posts and power lines.

Unfortunately, the decay process (if present) cannot be reversed.  If the tree is fertilized and watered correctly, it may survive for many years.


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Dr Stephen Vann


Plant Diseases and Disorders of Lawn Grasses, Trees, Vegetables,and Ornamentals


Plant Diseases Identification and Management

B.S. Botany --- Miss. State Univ. M.S. Plant Pathology --- Miss. State Univ. Ph.D. Plant Pathology --- Texas A & M Univ.

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