By Seaburngirl
East Yorkshire,
United Kingdom 
conifer damage
a colleague has a conifer hedge mixed leylanndii typr.
one started to show browning last autumn. he now says the neighbouring ones are also going brown. spreading from the first brown one.
any suggestions as to why/ what to do etc.
18 Mar, 2011
Answers
Could it be The cypress Aphid ??
18 Mar, 2011
Hurray, sounds like the Leylandii fungal infection! Can I have a branch to shove in my neighbours large hege?!
18 Mar, 2011
Alot of leylandi in my area have gone brown over the past couple of years. Once they go brown they will never recover. It could be red spider mite or some of the other suggestions made above.
18 Mar, 2011
ah well I'll tell him but I dont fancy a trip out to see it.
its not all leylandii though. can he spray it with anything [no paraquat is not an option :o) ]
18 Mar, 2011
sounds like the aphid 'blight', we have a hedge of some type of cypress and by spraying them [about now] last year we stopped the brown patches from spreading. Now they are all green again, so we will spray them this week just to be on the safe side. Can't remember what exactly we sprayed them with [sorry!] but found one easily at the garden centre.This is a commom thing with these hedges, but worth doing as they are a solid evergreen to have in the garden.
19 Mar, 2011
Previous question
Sounds a bit like honey fungus, Seaburngirl?
18 Mar, 2011