OK OK I know the most popular answer will be: "You can't" but
nonetheless: how do we control rabbit ingress?

My new employer has about an acre of garden, in which we're about to
create a new perennial border. The garden is out in the country, and is
bordered on one side by the road and the old (gappy) hedge, and on the
other sides by a standard post and rail fence. Across the fence is a big
field (10 acres?) which occasionally has a few sheep in, but is mainly
used for hay (I think).

Rabbits aren't a big pest yet in this garden, but they are around. Is it
possible to dissuade them?

I was thinking of nailing chicken wire around the entire perimeter. I
know that they burrow, but I figured maybe they only do that when
there's a vegetable garden to be got at.

BTW my employer is currently 'absentee' (working abroad for a few
months) and so can't be around to stand duty with a shotgun.

Any advice gratefully accepted!

Cheers
John