soak some rags in jeyes fluid and hang from bamboo canes about 18" and place them around the perimeter of the garden- have to resoak them regularly
we use to use something called renardine but thats been banned now cos it was carcegenic(like creosote)
or something like this- have used them and they work- but work best in the country side not so effective against urban foxes
http://www.g55.co.uk/acatalog/foxes.html we very often get badgers and foxes digging up lawns to get the crane fly larvae---- ruins the croquet lawns you know!!!!