This Hydrangea clings on by little roots that grow out from the stems, so you would need to twine it through the wire fence to begin with. After that the 'twigginess' of the plant would keep it on the fence. It usually takes 2 or 3 years to get established, during which time it makes slow growth, but once it's got its feet down it can grow about 4 feet a year in all directions.

My climbing hydrangea went in 2 years ago and grew 2 feet each year, so now is 4 ft and spreading in all directions; I do water it in dry spells and give a Spring feed of 'Growmore'. It clings all by itself [clever little thing!] but that is on a wall, however it will search for a leg up wherever it can even on wires, they are great plants.

Thank you very much to both of you.