In article , Juco
writes
I have a Leylandi hedge which I keep to about 2 metres high, but over the
years it has slowly increased in width (about 4 feet) I would like to reduce
the width but realise this will take the greenery away, Question is... will
it recover the greenery in a slimmer format and if so how long would this
take.

From experience (which is rare amongst the Leylandii knockers) you can
get away with it so far, some of the ones that you see where they have
been cut right back to the trunk stand no chance at all of regrowing but
you can trim back a fair way and still get growth. I have cut back a
neighbours 25 footers to 10' and they carried on like nothing had
happened, my current next door neighbour reduced the size of his hedge
from 6' to 3', realised he had made a mistake and let them grow to
5'again which they have done quite happily. I've reduced the thickness
of mine a couple of times with no ill effect but I have not cut back too
close to the centre, try cutting back say 6" from either side and see
how that goes

--
David