Leylandii Problem

[Stayahead]

Patches of brown (dead?) have appeared in 3 areas of my Leylandii. I trim them(I believe carefully the same time every year). Growth in the rest of the trees is flourishing. Is this a bad sign? Is this a sign that they are dying and can I do anything to prevent this spreading?
Many thanks for your help.

Terry Davis

[dannyk13]

Could be just wind burn.

[Old_Geezer]

I thought that was what one got after a good curry ?

[Old_Geezer]

https://www.rhs.org.uk/advice/profile?PID=263

Looks like it'll recover.

[maggie01]

We had this once and I was told it was caused by some insect but can't remember what it was

[tonyav]

Conifer aphid, maggie.

https://www.youtube.com/watch?v=7D8HrFGdwGU

[Stayahead]

Thanks to Old Geezer, dannyK13, maggie01 and tonyav for your helpful answers