Hole in My Holly ....

Hi,

The other day I spotted a smaal hole in the trunk of my Holly Tree, then when I touched it some bark broke away and black gunk flowed out.

Any idea what this may have been and if there is anything I can do?

Thanks, Nick

 

Hi nickp,

Looks like a case of bleeding canker caused by Phytophthora icilis. Normally cankers in holly only affect branches which can be removed to help reduce the spread of infection. Unfortunately in your case it looks like it has affected, or will soon affect, the cambium of the tree and damage the water-conducting xylem & phloem. I doubt the tree will recover from this infection, although it may live for a good few years yet.

 

Hey TreeSurfer, thanks for the response

Is there anything that can be done? The tree is 25ft tall and is one of a pair, so I'd hate to lose it.

Would a tree surgeon be able to cut our the bad stuff and bandage up the tree? :D

 

Hi,

If the canker hadn't got into the cambium then the next course of treatment would've been to cut around the affected tissue to stop it spreading. Unfortunately this infection looks as if it's gone straight through the bark and heading into cambium which lies behind.

If I can provide a lay person's view: It's like cutting your torso and having an infection go straight into your blood stream where it will travel around your entire body. Same for this tree. Once the infection is in the water-conducting vessels of the tree (the xylem) then it's going to spread.

Trees always deal with infection the best they can by trying to trap it in place. Basically the tree physically hardens the cells around the site of infection so halting its progress. Some pathogens are weak enough to be halted by this process and some are strong enough to break through it. If the pathogen does break through then the tree witll form another barrier zone again and again until it either traps it, or dies from infection-related failure.

I'm afraid you'll just have to wait it out. If the tree is healthy enough to combat the infection and produce reaction wood around the wound (a callus) then there is no reason why the tree should not survive for many years to come. However, sometimes an infection like this can lead to other problems such as structural weakening which you will have to keep an eye on.

Probably not quite what you were hoping for, but there's no real cure for a Phytophthora infection. Sorry.