HI ALL When and how do i grow vines and clematis

spring is a good time i believe .

You'll have to be a bit more specific with your query - first, vines - do you mean grape vine or just climbing plants generally? As for clematis, how to grow those isn't that difficult, needs sun or sun shade, soil enriched with compost before hand, buried deeper than it was when you bought it or laid on its side in the hole, with a mesh support to climb up. More important is choosing the right variety - sizes vary between 30 feet by 30 feet down to 6 by 6 feet in the climbing ones, some require pruning at the right time, some don't.

or 90 feet at least for my ornimentle grapevine .

With any vine, it is also important to provide support--if needed--BEFORE they are planted. There are few more risable and exhausting gardening shambles than trying to install a trellis behind a vine that has been growing wild for a few seasons!

and as well as what tugbrethil sais its worth giving some like my grapevine a hand so they go wear you want rather than wear they want .

Thanks for clarifying, Stephen! You already have the main structure built, but you may want temporary ladders of criss-crossed wire or string, so that woody vines can reach the top, or more permanent ones for herbaceous or annual vines. I'll admit that I am uncertain that there are any annual vines that would signifigantly cover a large arbor in a normal UK summer, but what do I know? : )

As I hinted before, the support needed varies with the plant - some twine, some cling, some need a thin support for their small twining stems to wrap around. Clematis (other than the big species varieties like Montana) need thin supports such as mesh, thin canes, string, etc - twiners need something stronger because the whole stem twines in and round something, others will cling to a solid surface like a fence or wall. Examples of the latter two would be - twiner, Passiflora, Akebia quinata, climbing honeysuckle, and for self clinging, Parthenocissus.
Basically, it's a bit more complicated than it first appears in terms of what plants to choose for the supports you have.

Thankyou Tugbrethil & Bamboo