"Tom Woods" wrote in message
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I am wondering if there are any climbing plants i can grow over the
top of it that are spikey or unpleasant in some way?

I have used Albertine rose. It is a very fast climber and has huge thorns.
The main problem, from a gardening point of view, is that, being an older
species, it is prone to plant diseases and has a relatively short period of
flowering. Firethorn is also recommended for planting inside the wall, while
Hawthorne makes good, relatively fast growing hedges.

Colin Bignell