By Hank
Cheshire,
United Kingdom 
Oh dear, seems I got the leylandii wrong.
My 35 yrs old rowan tree died early last year and I needed something quick growing to replace it, so bought 4 leylandii in pots, 4 ft tall and planted them as they were. They're now 6-7 ft tall and at 8ft ( same as the rest of the hedge) I was going to stop them and expect them to thicken out.
According to my good pal Bamboo I have this quite wrong. Should I now cut them down 1/2 way and expect them to produce a new leader ? Photo below
28 May, 2014
Answers
Thanks B, I wondered if you'd say that. I'll certainly give it some consideration.
But a further problem is the rest of the hedge, which shields us from the house behind, the path of which is 2 ft higher than ours. We like the privacy, and a suitable fence would have to be be very tall indeed.
28 May, 2014
I suppose I meant a less rampant plant, perhaps Thuja occidentalis instead, rather than a fence...
28 May, 2014
Ah, thanks B, I'll check it out.
28 May, 2014
Hmm, you must have been reading my answer to someone else's question Hank! It's really hard to look at your photo because it's upside down...
It's only 4 plants, not a full hedge, and they look as if they've plenty of growth near the bottom, but I'd certainly reduce the top by a third to a quarter, and trim them back at the sides in a conical shape...
(Actually, if I'm honest, that's not what I'd do at all, I'd take the things out asap and get something else, couldn't be bothered with the ongoing fight to stop the things taking over the universe... life's too short to be hedge cutting 4 times a year, but hey, we're all different...)
28 May, 2014