Wisteria sinensis – a vigorous, deciduous twining climber, suitable for growing on trellises, pergolas, and walls; also it can be trained as a standard – and the examples I have seen, in full flower with heads more than 4′ across – magnificent. I’m reading from the RHS Encyclopedia of Planting Combinations for further information…
The long racemes of usually lilac-blue flowers are borne with extraordinary profusion and combine successfully with early-flowering clematis such as the montana cultivars, early ramblers like the Banksean cultivars, and ceanothus. The long racemes hang down below pergolas and arcades, or trained lower down, can mingle with shorter shrubs, such as genista or berberis, with herbaceous or bulbous plants, such as the taller alliums and crown imperials.
Wisteria enjoys plenty of moisture at the roots and is a classic climber for trailing along rustic bridges and fences near ponds, where the lavish display can be reflected in the water.
In areas with warm summers, Wisteria sinensis will produce plentiful bloom without sever annual pruning, allowing for a much more informal effect than would be seen on spur-pruned plants kept trained close against a sunny wall. Clematis montana, combined so, is of comparable vigour and will remain, at least for a few years, in equilibrium with the wisteria.
What isn’t mentioned in this excellent book is the fragrance, spicy, peppery, intense and scaled up to a mature specimen, wholly intoxicating.