What's Attacking My Trees?

[Palmela]

The brown patches on my trees are getting bigger. Any ideas what might be causing this? I'm pretty certain it isn't something dropping onto them. The plants are a little under 20 years old.

[Wacky Racer]

Exactly the same thing happened to my conifer hedge in my back garden about eighteen months ago, my gardener said it could be to do with drier than usual conditions this last couple of years, he advised not trimming them until they recover.

This picture was taken this morning, they are looking a bit ragged because they have not been trimmed last year, but the green is starting to return, six months ago they were 80% brown.

[paulw123]

https://www.rhs.org.uk/biodiversity/cypress-aphid

In my experience it's usually this. Dry summers don't help. I cut a lot of hedges and it's getting worse the last 10 years or so. Most leylandii is affected to some degree now.

[Palmela]

I did spray the brown bits with what was left of the stuff I used on my box hedges against moths. Guess I might have to research something more specific.

[Wacky Racer]

paulw123 said:

https://www.rhs.org.uk/biodiversity/cypress-aphid

In my experience it's usually this. Dry summers don't help. I cut a lot of hedges and it's getting worse the last 10 years or so. Most leylandii is affected to some degree now.

Yes, I read about this too, my hedge has been fine for twenty three years until recently.