Jojo, I've come across Clematis montana and there are several varieties of Wisteria, sinensis being the most common, but I think you're mixing up two different plants.

Or maybe I'm the one that's confused! Are you asking if it's safe to plant BOTH Clematis montana and / or Wisteria sinensis to climb against your house?

Yes I would like to plant both these plants, I have a brick arch over my back door so was thinking of a type of clematis. I also love wisteria but do not know to much about them. My new garden is a bit of a blank canvass at present so mulling over some ideas. All advice gratefully received!

Hi Jojo I have a westeria and a montana and the montana is on a fence, the wisteria on a wall. The clematis needs wireing so it can climb across or up, nothing fancy either good string or wire covered with plastic. As it grows fasten nice and securly as wind and weight will sometimes pull it off. My wisteria has a wire which is more heavy duty and have used proper screw in eyes so it is more sturdy as mine is a few years old now and surprisingly heavy. To maintain your wisteria look up Alan Titmarsh as his method for pruneing is brilliant . Neither of the above mentioned plants have caused any damage to the fence or wall so hope this helps a little . Remember a shrub can be pruned to the size that you want :)

Thats great thank you for your help,I will have to upload some pictures of garden as is and plan from there!:)

If you just want something over the arch, don't, whatever you do, plant either montana or Wisteria - both get more than 30 feet, so stick to one if you must have either.