my evergreen heges are going all brown and dead.

[gnasher]

there about 20 years old .are they just dying and have to be replaced ?

[darth vader]

in theory they should last for ever - what exactly are they? (i.e. privet?) could be diseased but they are very sturdy usually. do they separate you and your neighbour? has your neighbour complained about them recently? (what i'm getting at is perhaps a slight possibility of poisoning - with disease it would attack one area then spread out, not the whole hedge dying just like that). can you give more details please..... btw if they are diseased then you need to do a bit more than replace them as the replacements will get diseased also i.e. treat the area first

[Robinia]

Your hedge could have suffered in the long, hot, dry spell last summer &, coupled with the strong cold winds we've had over winter, may be dying back. I live in the midlands & have lost a shrub & plants in a dry windy part of my garden.I'm afraid if it's a conifer hedge it won't regrow.