The message
from "nambucca" contains these words:

avoid leylandii, whatever you do.

:-)) .... Nonsense.
Leyllandii do grow pretty quickly - and, if you have a mind to, can be
kept to whatever shape you desire.
They just need regular trimming. The more often you trim, the denser
they become. So long as you remain in control, it will do the job.

--
ned (Leylandii Preservation Society, founder member.)
;-)

But at only 5 ft away from a conservatory and growing to 8 ft the roots of
Leylandii could be a problem ..........they sure are in our soil

Nah, they won't undermine anything, and I wouldn't think OP would be
trying to grow anything else there except perhaps, bulbs.

--
Rusty
Open the creaking gate to make a horrid.squeak, then lower the foobar.
http://www.users.zetnet.co.uk/hi-fi/