On 06/04/2015 20:25, kev wrote:
We are planning to plant a hedge of Leylandii and will let them grow to
about 6-7'. What would be an ideal distance from the boundary 16-18"?


I confess I agree with the others: Leylandii and Lawsonii make good
masters but poor servants. You'd be better off planting a Yew hedge.
It's evergreen. It's one of the smartest hedges there is. It can be
clipped tightly without going brown.

If you want a 6ft hedge (to keep within the law), I suggest you aim for
5ft, as the growth will always run away from you. Even if you keep your
side trimmed, your neighbour may not trim theirs until it becomes a
nuisance. A Yew hedge will cope with that; Leylandii/Lawsonii will not.
--
Spider.
On high ground in SE London
gardening on heavy clay