[wbmkk]

Most plot holders on the allotments have timber framed chicken mesh barriers around their vegetable beds, made from roofing laths and chicken mesh.

In the USA they use electrician PVC conduit, rather than timber which I think looks better and would probably last longer.

I'm thinking of making up panels of approx size 3m x 0.6m and simply join at the corners with cable ties. For each panel, which would have a central support I would need 2 x 3m lengths, 3 x 600mm lengths, 4 elbows and 2 T pieces. Maybe I might even consider having 2 intermediate supports.

Would this be suitable please ?

[Trillium]

I used exterior conduit in my garden against the same problem. We spaced the verticals out enough so that the ultra cheap plastic netting we got from the dollar (pound) store wouldn't sag. We went through a hard winter with masses of snow and we were surprised that not only did the cheap netting 'roof' hold up under heavy snowloads, but the rabbits and mice didn't go anywhere near the blueberry plants within. No holes chewed through or anything. Any sort of netting scares them off.

Construction wise, we cut conduit pipes to fit inside each raised bed and I bought pvc corner pieces, T pieces for overhead support/strength, etc and just popped everything together for easier takedown if we want to take them down.  Basically I have a tall rectangular box with a base that fits snuggly into the raised bed, and it's 5 ft tall because my tallest blueberry bushes are 4.5 ft (1.5M) high and a netted roof to keep out birds. To access the fruit, I simply tip over the whole cage as I couldn't bother with or afford fancy entry doors and such as seen in some youtube videos.

So yes, your spacing should work depending on how tight you fasten your netting/whatever.