Wisteria venusta Okayama

Wisteria venusta 'Okayama' is a variety of Japanese Wisteria with slow growth, infinitely graceful, which will seduce with the abundance and wonderful fragrance of its spring flowers. Its flower clusters are rather short but well supplied with dark purple buds that open into large pea-like flowers of a lovely purple-mauve colour. Hardy and as accommodating as its Chinese or American cousins, it is the least vigorous of the Wisterias, ideal for small spaces. It also has another major advantage: the gardener will not have to wait for many years before admiring its flowers.

The Okayama Wisteria is a horticultural creation selected in Hokayama, Japan. Its wild ancestor Wisteria venusta (=brachybotrys) is a Japanese botanical species of modest stature also known as the Silky Wisteria. It is a deciduous climbing plant producing long twining stems that wrap around their support in a counterclockwise direction. Its root system is deep and trailing, composed of fibrous roots that live in association with bacteria and mycorrhizae. This indicates a good adaptation to poor and fairly dry soils.

The Okayama variety, with relatively slow growth, reaches an average height of 4m (13ft). It can be pruned as a 2m (7ft) bush in all directions. The plant blooms in April-May, while already carrying young bronze-coloured leaves. The inflorescences are produced profusely. They are pendulous conical clusters, compact, measuring about 20cm (8in) long, still tightly closed when the buds take on colour. The mauve flowers are large compared to those of other wisterias.  Their complex fragrance reveals notes of jasmine, orange blossom, caramel, and honeysuckle, somewhat reminiscent of Spanish broom with a hint of camphor and cloves.  The fruits, shaped like velvety beans, measure from 10 to 15cm (4 to 6in) long. The leaves, 20 to 35cm (8 to 14in) long, are divided into 9 to 13 leaflets of a medium green colour, ovate, each measuring 4 to 8cm (2 to 3in) long. They turn a very warm yellow quite late in autumn before falling. Branches and leaves are slightly pubescent.

Wisteria venusta 'Okayama' is perfect for covering a wall, a railing, a pergola, an arbour, or a porch in romantic gardens, including small ones. While wisteria branches can usually entwine with the sturdiest trellis, this variety is much more "respectful" of the supports that welcome it. Plant it also in a large container on the balcony or terrace. It will pair well with a Mayleen clematis montana, a Purpurea Plena Elegans clematis, some perennial peas...