Further to our conversation on the 'gorgeous flowering vines' thread... I couldn't find my pictures of the pergola walk in summer so we swung by today and took some more. It was a damp and gloomy day and the flowering things were 'past it' so green and brown are the dominant colors. The pergola walk feature is a great demonstation of a large variety of vines, and growing and pruning techniques. The 'walls' are very interesting and I think you should consider doing something more interesting on your pergola that just to grow vines vertically up it...!

The pergola walk at RBG is quite long. It's in two pieces that form an arc that enclose the formal rose garden, with the tea house in the center. This is not the best of pictures and it only captures part of it, but you can see the two arms of the pergola extending out from the tea house:

This is a view down part of one arm of the pergola:

DH in the picture to show scale :-)

Horizontal espalier makes a nice 'wall'. Espalier material included climbing hydrangea, various fruit trees, hornbeam, wisteria and kiwi - and a few others but I didn't check what they were!

This was climbing hydrangea:

This was an apple tree:

Wisteria was both horizontelly trained as well as had the trunks arranged attractively:

This was a fan-trained fruit tree (I didn't check what kind...)

Here are two trellis espaliers and and odd/whimsical window. The heavier trellis is hornbeam; the lighter/younger one is 'Snow Cloud' crabapple. The 'window' is euonymus.

A closer view of the 'window' - which I think is a bit weird!

Clematis and smaller roses were grown up a mesh that was almost invisible from a distance:

A closer view of the mesh:

I really think you need to plan to enclose the pergola a bit to have it fit comforably in the landscape. Hopefully the RBG pergola walk pictures give you an idea of how you might do that in a creative way with plant material that will add interest year round to the pergola and patio. Espaliering some fruit trees would be fun, attractive and productive. I'd be inclined to try that on one or two of the panels and flowers on the others.