The message
from Jimbo contains these words:

Hi all,

I have a newly planed beech hedge around 5 ft high and quite spindly - I
want one section of hedge to be around 4ft high and another to be around
10ft high. Obviously I want it to fill out and be quite dense but would
like advice on the best way to do this. I was thinking of perhaps laying
the hedge on the lower hight part - rather than chopping the tops off.

I wouldn't attempt to lay a newly planted hedge; its roots won't be
strongly enough established for growth to recover.

A spindly 5ft hedge won't thicken at the bottom,(where you most want
it for future shaping when it's either 4 or 10 ft high) so you are
probably looking at some severe surgery in a year or so. But let it
establish some root system first.

Janet.