my clematis already 3.5 metres tall should I cut it so it reshoots?

Hi, you don't say what variety of clematis you have? It may be it is a variety that needs a more sunny position. Or as it seems a very fast growing type might be better twining round tree etc. I'm certainly no expert on clematis but think they come in 3 groups for pruning purposes. Did you cut it back once it had died back or just let it be? If you don't want to move it, maybe you could just try cutting it really hard back at the end of the season. Check the variety and position first if you still have label.

Different clematis have different pruning requirements. You need to know which one it is before it is safe to think of pruning. That said I would never let a clematis get to 3.5 metres

Except the montanas and armandii, Moon grower??

Lightning, could you please post a photo or tell us the clematis's name? Then we can advise on when and how to prune it.

Hi Spritzhenry no I don't let my montanas get more than 2 metres - they are climbing up the side of the potting shed and we do not want them on the root. S oevery year they get a serious haircut and flower perfectly well.

Understandable! As you know, I have some on the house wall and one up a tree - so no problem in growing as high as they like - and do!