On Tue, 15 Apr 2003, David C wrote:

My question is should I take the tops out now, I understand this will
encourage sideways growth but will they still grow up and if so how
fast ? Alternatively should I wait until they reach the required
height and then top them ?

There have been similar questions in the past (recent as well). If you
top at the height you want, the trunk will be visible (from the right
height), so top them a little bit earlier (half a meter perhaps?
Check the archive). Don't worry about them not growing further, they
do, and they do so fast. They not only develop a new leader (perhaps
leaders :-) but also-more slowly-expose their trunk at the bottom as
well.

Aim to trim once, probably twice a year (I have them done in autumn).
Don't prune to the old wood; I think I read here recently that
Leylandii regrow, but I guess they take their time. The Lawson may not
regrow.

A request: don't feed the discussion about Leylandii; regardless if
it's justified or not, there are at least 2-3 threads running in
parallel about it at any given time.

Kostas