On 16 Sep, 21:22, Mike Barnard
wrote:
Still waiting on land registry results, but the consensus is (if we
can get planning) to put up a steel fence with a climbing, thorny
plant on it. Any reccomendations for this plant? Something exotic and
lethal?

Pyrethrum.

- Extremely dense, impenetrable, strong, interwoven web.
- Covered in long conical spines that are robust, sharp, vicious.
- Foliage continual all round, dark green, IIRC red berries.
- Grows quickly, easily forms an impenetrable 3-5-9ft hedge.

Whizz along it with a hedge trimmer & recovers even if savaged.
Needs no care, favoured where "problem entries" run alongside gardens.

Indeed forget the fence, just create a hedge of pyrethrum.
Attractive, inoffensive, but mess with it and it becomes razor wire
that grows.

There is one worse, but that requires multiple rows to get a dense
hedge.
Ask a good garden centre, shop around carefully.