"Bob" wrote
Your only real option is Rabbit Fencing, and make sure you bury it at
least 6 inches deep all round and check it every few days for digging. You
also need to keep it weed free to be able to check it.
Regards
Bob Hobden

Thanks Bob, I was afraid of that. Rabbit fencing isn't really practicable
due to the nature of the site, but I could probably do certain patches.
The pots of Dianthus I was looking at have the appearance of reasonably
tough leaves. I will try one pot in a corner, where it might not get spotted
until its got some roots down, and see what happens!