In article , Martin Sykes
writes

I'm planting a native hedge which isn't going to be a problem height for a
few years. When it is though, how is the height llimit enforced with respect
to the natural growth of hedges through the year? I'm thinking of something
I heard that trimming native hedges every year is damaging to the wildlife
and it's better to do it every three years instead. Something to do with
production of fruits etc. being better that way. If I do that though the
hedge will necessarily fluctuate in height between about 6ft and 8-9ft or
more. I imagine trimming a hedge to exactly 6ft every couple of months for
legal reasons would be bad for the hedge for wildlife reasons?

I think that these are some of the factors which are holding up
completion of the Act to be passed. That said, there's no excuse for
some of the 40/50/60 ft. examples of leylandii hedge to be seen.
--
Alan & Joan Gould - North Lincs.