Gosh, that's bad, isn't it? It almost looks like a pest with a pair of scissors! Apart from the slight possibility that it could be birds for some reason shearing off the shoots, I would have said slugs or snail damage - no silvery tracks anywhere? They can hide themselves very efficiently in the daytime, especially if you have a wall that isn't too well mortared. I very much doubt that woodlice have done this. How far up the wall is this happening? You aren't by any chance anywhere where you'd find deer, are you? (just a long shot - they get everywhere, even in towns, I believe)

I don't think anything is coming out of the wall to cause your wisteria. The wall itself has a healthy crop of lichen which would not be there if the wall had any nasties in it. I really suspect this is slugs and snails that tend to graze when there are no humans around.

Thanks both for replying. I haven't seen the tell-tale silvery tracks ... but who knows.

I wouldn't mind too much if it was deer eating it ... would love to see deer in my back-garden ... never seen one in real life :D

If they are slugs n snails ... how am I going to stop them? They eat my lupins, primroses and delphiniums ... but because they are on the ground I can put the pellets ... but what can I use on the wall?

Btw its quite high up the wall - 4 - 5ft.

I was wondering if it could be ants?

I very much doubt it'll be ants. I'll have to think about that one, but I'm sure there'll be someone on here with the answer!

Ants do not eat plants... they milk the aphids for their honey dew. Given this is a super old wall with lots of places for the slugs and snails to hide you are going to find it difficult to catch the blighters. To be honest I'm puzzled as to why you want to hide the wall - looks like a good solid stone one to me, if it were breeze blocks are cement I could understand. You could try erecting a trellis a foot in front of the wall and growing things up that.

Its got a lot of missing mortar, MG and it looks a bit run down. In the middle of it there is a red brick walled up "door". I think at some point there was a gate from the back garden into the park. The house is victorian and I think this is an original boundary wall. It just needs to be fixed really. The trellis idea is a good one though.

Been out with the torch ... you were right GM and Gattina. It is the slugs! they are perched on each stem munching away! Now the trick is how to get rid of them!. I've seen quite a few on the ground so I will put the pellets but not sure how to stop them climbing the wall ....

They won't be climbing the wall, GF, they'll already be living in it. I still haven't come up with a solution to that one, but I'm working on it.......The best solution for the time being is that you get out there at dusk or after it has rained, or very early in the morning and pick the little blighters off and kill them there and then. Not ideal, but it'll reduce the numbers radically.

Dangling or trying to fix cans or plastic cups of beer might work in this case GF.Or slipping pellets in to any cracks in the wall that will take them .

Yes Susie, I have been trying to think of way of dangling the beer ... my other half has been laughing his head off at thought ... but I'll have to give it a try.

I had quite a chuckle myself this morning, trying to picture an array of beer cans hanging all over your wall: Even if it doesn't get the snails, it may win the Turner Prize!

I've stuck pellets wherever I could see crevices in the wall and plenty on the ground ... we'll see what happens ... if I ever get to hang beer cans on the wall ... I'll post a picture for everyone's amusement :D

You're already turning into a seasoned Goy, GF. Quite mad! Hooray \0/

GF use the actual cans and only leave an inch of liquid in the bottom, the slugs will be able to get in but not out!

My dear Wisteria and I are WINNING!!! GF 1 - Slugs 0. Yesssss.

LOL its only temporary really ... but at least now I know for certain that it is the slugs that were eating the poor thing alive faster than it can put shoots out. 36hrs after I turned the wall blue with slug pellets ... the Wisteria has about 6 new shoots all about 6 inches long and more plus loads of other just starting up!!

And I could see the evidence of the little blighters liquified over the pellets!

I never thought I had such a mean streak LOL ... these slugs ... they bring the worst out of me!!

Fingers-crossed I can keep on top of it.

Oh you've made me laugh out loud! I think most people on this site get a touch of the Daleks where slugs and snails are concerned - "Exterminate!"
I once proposed getting an air rifle to see off the marauding pigeons in our garden, when my hippie sister-in-law protested "Pigeons have rights, too, you know! In fact, so does EVERYTHING in the garden - even pests!" then there was a bit of a pause "Except snails, of course." So, you see, you're not alone.
I must admit to using pellets, but go round first thing in the morning to stamp on anything writhing and frothing - I hate to prolong suffering in anything. My Dad used to go round with a box of salt - yeurgh!