There is a legal maximum height a hedge may be!!

If you are thinking of planting Conifers, then the maximum height is 3 meters, then the neighbours can force you to cut it. Also they can stop you (certain trees and shrubs) because of possible root damage to foundations.

Check with your local council planning office. They generally know and are quite helpful.

Hi Saxonman - does this apply to new hedges or established ones? Our [south-side] neighbours keep their mixed conifer/decidious hedge tidy,but it is HUGE and as the garden slopes downhill it is well over 3 metres high, probably nearer 6mtrs! My garden is always in shade, except in high summer when the sun is right over the garden.

it is to do with when the law was braught in about conifers .the main reasen was everyones faverite laylandi which you now need planning permission for as they grow outragesly big and fast.its like seat belts in cars ie older cars before the law came in dont need to have them.id imagine it would be hard to know how long your neighbers 6metre tall hedge has been there im afraid.its still worth asking your local council as saxon sais you never know.

Have a look at Prunus laurocerasus -it will eventually get bigger than you need, but will make a good dense hedge in shade.