Our cat had a habit of climbing up the corners of the polytunnel,
resulting in a myriad of claw puncture holes on all four sides.
Having tried a number of different solutions to this problem I finally
cut up four pieces of tunnel polythene and using tunnel repair tape,
stuck them to each corner, so that the poly formed a flapping tube
about three feet from top to bottom, the base of the tube being about
a foot or so from ground level. It looks a little unsightly but it
has stopped the blighter from perforating the polytunnel!

Cheers,
Compo.