Decaisnea fargesii, also known as the blue bean shrub or dead man’s fingers, is a deciduous shrub native to the mountain regions of western China. It belongs to the unusual Lardizabalaceae family. Decaisnea fargesii is the only shrub in this family—the other members, such as the Akebia, are all climbers. Much like Akebia, this plant is admired for its unique, large, decorative fruits that resemble blue cucumbers. The species was discovered by missionary and plant collector Father Paul Farges and named after Joseph Decaisne, a Belgian professor who worked at the Jardin des Plantes in Paris.
Characteristics of a Remarkable Shrub
This large, multi-stemmed shrub can grow up to five meters tall and wide. Its narrow base of stiff, arching branches creates an umbrella-like shape. Even in winter, the pale stiff branches with large pointed buds add ornamental value. The branching is tiered with a generally upright growth habit.
Decaisnea fargesii is best planted as a solitary shrub in a spacious spot, ideally in the understory beneath larger trees. Since it leafs out late in the season and has an arching habit, it pairs beautifully with lower-growing plants such as bulbs and perennials that prefer sun in early spring but tolerate shade later in the year. Its leaves are large and pinnate, with individual leaflets about eight centimeters long, and leaf stalks reaching up to a meter. This foliage gives the shrub an exotic, tropical look. In June, the plant produces clusters of bell-shaped, yellow-green flowers, though these are not particularly showy.
The Fruit of a Contrast Plant
The fruit of Decaisnea fargesii is a long, cylindrical pod that truly steals the show. Initially a dull green, the pods ripen to a striking blue in October. Because of their knobbly structure and unusual color, the fruits are commonly known in English as “dead man’s fingers.” Together with the shrub’s golden-yellow autumn foliage and striking gray-blue older branches, the fruits make it a true contrast plant.
The pulp is translucent and jelly-like with a slightly tart flavor. The seeds are large and brown. While other members of the Lardizabalaceae family produce fruits that are marketed for consumption, Decaisnea’s fruits are more difficult to open and are not found commercially. However, the pickle bush is perfectly suited for use in a food forest or edible garden.
