Akebia quinata is commonly called the Chocolate vine and is a climbing plant that is semi evergreen and a very vigorous grower. It has green leaves or leaflets in clusters with tendrils and develops chocolate purple flowers in the spring. It was a new plant to try as a bonsai and here is one I am trying to develop currently.
I bought this one from a local garden centre back in 2010 after being advised that they do grow fast and make a good bonsai. It was in a normal flower pot and in order to get it home I reduced it down to around 0.5 metres in height instantly as it was a tall climber at point of purchase. The trunk was around the thickness of a pencil with a slightly thicker diameter base. I then proceeded to re-pot it into an air pot and cut the roots back hard as there was a mass of root and it was fairly pot bound. I then further reduced the top down to 15cm and it did look a bit sparse. I then placed the air pot within a flower pot for some extra protection and allowed it to recover. By 2011 it was developing well and flowered a mass of chocolate / purple flowers and produced lots of climbing tendrils which I pruned off.
This year I re-potted it, the fibrous root pad has developed well within the air pot and the roots are evenly spaced and do not girdle due to the air pot. The trunk has really started to thicken and it is forming the start of a crown but side branches are slow to develop. It has grown well and the leaves are still slightly large but overtime I aim to work on reducing the leaf size as part of the crown development. I am pleased with the development so far over a 2 year period.
There is a white form of the Akebia which is Akebia quint ‘Shirobana’ and this is a recent introduction from Japan and I was given one of these to try last year so I will post on this as it develops and so far is proving to be a good grower but it did not flower so profusely as the chocolate form.
There are a range of climbing plants used for bonsai, and it is worth experimenting as the growth rates and stem thickening seem to work well. Jasmine, Ivy and Wisteria are also others I would recommend to try.