In message , boombangabang
writes
A word of warning -
using a hedge trimmer off ladders is not to be recommended, particularly
if the hedge is 100 cms thick in places.

What has the thickness of a hedge got to do with a ladder. You should
not be using a ladder anyway, you should on steps.

If the hedge is very wide, you should be using a pole trimmer

First phrase - 'using a hedge trimmer off ladders is not to be
recommended,'

Second phrase - 'particularly if the hedge is 100 cms thick in places.'

If the hedge is as wide as 100 cms the user of a standard trimmer would
have to extend their arms in order to cut the far side of the hedge,
increasing the possibility of loss of balance.

As indicated in my text, a long reach trimmer is safer.
--
Robert