snip
I wish to block the gaps with a fast growing evergreen in order to
prevent the local low life getting any ideas about plundering my stable
yard, also to give birds somewhere to shelter.

kate

I don't know where you live, Kate but perhaps Escallonias would answer your
need? They grow pretty quickly and have lovely flowers, beloved by bees.
The other possibility is Eucalyptus which also grows fast and tall. If the
height isn't what you want, there are some varieties that can be 'stopped'
and make good hedging plants. Holly isn't quite so fast but it's a good
deterrent and if you get male and female varieties, you'll get the berries,
too.

Some good ideas Sacha, Escallonias would be a goody, would Macrantha be
a good choice, I dont know much about it I am just looking in a book at
the moment and it tells me that that one grows large and vigorous.

kate Sth.Glos.