Are we talking the Montana type .....they certainly spread
ours this year had goldfinches on the first floor and the blackbirds up above.....maybe time it was cut back again ☺

Does not need to be of the montana type as want to scramble underneath.

Not sure then, our gardens too windy for anything else ...

Scotkat we have to prune back our Montanas several times a tear as so invasive... Have you thought of other species?

There is an excellent website from Taylors clematis. In it the different types of clems are explained, time of flowering, pruning, size and colour are all shown. It is well worth a look. If you see something you like then it will be easier for members with the preferred clem to describe their experience of it. If you mean scramble underneath trees etc then you will find it in that website. They come up to Gardening Scotland every year and they are always very busy which should give some indication that their plants grow up in Scotland.