Acer with coral spot. Any advice?

[Bolt]

 

 

[Chris at eden]

3 hours ago, Excels1or said:

Often think about this.....If we prune trees in the winter during dormancy, CODIT doesn't occur until Spring, so we may as well prune in the spring.....for many trees Spring is a bad time to prune, so wait until the summer before spores are high. Have you got any links you could share?

Sligo said you can prune anytime of year as long as pruning cuts are good.  Spring can be a problem for trees that are prone to silver leaf disease such as cherry. Plus, energy reserves are low after leaf flush. 
 

There is a lot of debate about pruning time and as I said, lots of info still recommends winter but you said it yourself, no wound response in winter.  
 

You can find references for both options but we had this conversation when I was doing my level 6 and it was concluded that summer is best phonologically.
 

if you prune properly though it’s all pretty irrelevant apart from issues such as silver leaf. If you wack the top out of mature trees and leave 15” diameter cuts it doesn’t matter when you do it, it’s bad. Yeah most will regrow but they will look rubbish and be defective.  If you focus on target pruning and minimise cut sizes it’s unlikely to be an issue.
 

[Chris at eden]

3 hours ago, Excels1or said:

Why flush cut?

It was recommended practice during the 1800s and early 1900s.  I still hear gardeners say it and I have seen it written on RHS online publications.  It was obviously rubbished notably by Shigo but it was noted before that by other scientists but they couldn’t dissect trees properly before chainsaws became available. 
 

[Excels1or]

23 minutes ago, Chris at eden said:

It was recommended practice during the 1800s and early 1900s.  I still hear gardeners say it and I have seen it written on RHS online publications.  It was obviously rubbished notably by Shigo but it was noted before that by other scientists but they couldn’t dissect trees properly before chainsaws became available. 
 

I suppose the first 3 walls of Codit have already taken place before the external branch collar compartmentalise?

[logwood]

To reduce surface area for infection and to the collar where healing cells are??

[logwood]

Here are some better pics….

[logwood]

[Excels1or]

Stupid question, thats not a nail in the tree is it?

[Stere]

The old myth about copper nails used to kill trees thing?

[daltontrees]

21 hours ago, Excels1or said:

I suppose the first 3 walls of Codit have already taken place before the external branch collar compartmentalise?

Yes, walls 1 to 3 are passive. Only wall 4 is an active response to wounding. As Shigo says, pruning is wounding.