Holboellia latifolia . (Broad leaved sausage vine)

Dense, leafy, vigorous and evergreen. The only other climber we do with those attributes is Clematis armandii but clematis are always thin at the bottom (all they want to do is reach the top of the nearest tree). This isn't. It'll form dense foliage all over whatever it's growing up or over. The smell of the small creamy pendulous flowers in April is nothing short of delicious. We used to do a hardier species - Holboelia coriacea - that looked similar but the flowers were less delicious in the smell department. It was a good looking plant (similar) but much hardier and we thought that would make people in colder gardens buy them. We were wrong. Holboelia will cover a house given half a chance but responds well to a good haircut and is easy to control. It will get slightly defoliated (leaves drop off) in cold winters but it always recovers. Avoid chalky soil but otherwise unfussy. Will grow in shade but probably prefers sun. 

One of the buildings at Kew Gardens (the Wood Museum, I think) used to have this growing up the front. The memory plays tricks but the impression I had was of an enormous tsunami wave of Holboelia latifolia that had washed up against and almost obscured the fine front of the large Georgian building. Enormously thick at the bottom, rising up to the gutter and curling over at the top. I suspect it's been removed. Even by my standards, it was a bit mad.

All our plants are propagated by us from cuttings that originally came from a plant in a village called Grafty Green in Kent. Supplied by a man called Tom LaDell, many years ago.

N.B. When clipping several plants with the same tool, have a bucket containing a 5% bleach solution and swish your blades around for 30 seconds between plants to sterilise them. This will help avoid the chance of cross contamination of disease.

As with all woody plants, plant high, exposing as much of the taper at the base of the trunk as possible. Allowing soil to accumulate round the base of a tree can be fatal. Keep very well watered when first planted.