"John McMillan" wrote

There's a real gap in the market for a book titled "Security Plantings",
describing all the spiny thicket forming plants which are actually
in some other way horticulturally attractive. It would have a section
on screens and possibly a (very thin) section on attempts at cat-proofing.

No, a very thick section of cat proofing, a very thin section on 100%
successful cat proofing.

--
Regards
Bob
In Runnymede, 17 miles West of London