Decumaria are a genus of only two species belonging to the Hydrangeaceae family. They produce aerial roots to cling to walls, fences or other tree hosts just like the climbing hydrangeas or schizophragmas to which they are very closely related. Decumaria thrive in sun or shade although they flower better in full sun.
D. barbara is a semi-evergreen climber growing eventually up to around 25-30 feet. It has ovate or oblong glossy, dark green leaves and corymbs of white hydrangea-like flowers in June or July. It is native to the SE United States where it climbs the trunks of trees. The flowers are slightly fragrant and they fade from white to yellowish white. D. barbara can be grown effectively as ground cover but, at Burncoose, it puts on a fine display in summer on a wall beside the entrance to the nursery.
D. sinensis originates from China and is considerably rarer. Burncoose have only begun to stock it recently. It is not quite as vigorous as the US species but its flowers are far more strongly scented. The flower heads appear in May in numerous corymbs and smell of honey. This species was first discovered in China by Ernest Wilson in 1908. It received a RHS Award of Merit in 1974.
Both Decumaria are perfectly frost hardy and will grow well in any loamy and well-drained soil. Little pruning is necessary but a light trimming of the new shoots after flowering will suffice.
Propagation from semi-ripe cuttings in late summer or early autumn as for most evergreen plants of this type.
