Japanese Hydrangea Vine – Schizophragma Hydrangeoides

Szczepan Marczyński

It’s a close relative to Climbing Hydrangea (Hydrangea anomala subsp. petiolaris) and has similar requirements and the growth habit, but can boast more attractive flowers than her cousin. Small, creamy white, honey-scented flowers are borne in densely packed large (25 cm in diameter) flattened cymes. They appear from the end of June to the second half of July. Its main attraction are large (3-5 cm), white petals of sterile flowers forming a garland around the flower. It has wide oval-round coarsely toothed leaves that are green in summer and yellow in autumn.

You can find on the market an attractive cultivar of Japanese Hydrangea – ‘Moonlight’. It has silvery-grey shading on the upper side of the leaves and grows quicker than the species.

‘Roseum’ is another interesting cultivar, though still rarely found on the market. It has pale rose flowers that appear in July. Heartshaped deep green leaves with a slightly red tinge turn yellow in autumn.

Japanese Hydrangea vine is native to the mountains of Japan, together with Climbing Hydrangea, and can be found climbing up the trees or sprawling at their base. It thrives in humus soil, light and moist but not waterlogged. It doesn’t tolerate drought. It prefers acid soil.

High air humidity encourages luxuriant growth of Schizophragma. It grows best on a site with a northern aspect or in semi-shade, and sheltered from violent winds. Young plants don’t like direct sunlight, whereas older plants will benefit from having their upper part in full sun and flower more profusely. Schizophragmalooks at its best when climbing up an old tree, but it’s also well suited for planting next to a wall, a rock or other porous support as well for growing over a wooden fence, an arbour, a pergola or any other sturdy support.

It’s not suitable, however, for training up fences of a light construction, such as wire meshes, as the mass of greenery produced by Schizophragma is too heavy. It can grow without support, as a picturesque ground cover plant, reaching in such case 1-2 m in height. When you plant young Schizophragmas, it’s best to lie the stems on the ground or to tie them up to supports in order to strengthen brittle stems until the aerial roots develop and the plant supports itself.During the first two, three years after planting it grows rather slowly, as all the energy of the plant goes into creating the root system. Once it’s well settled, and the roots reach groundwater, it starts growing very vigorously producing more than 1 m annually. It can start blooming in the 2^nd-3^rdyear after planting. It doesn’t require pruning, but will tolerate well trimming of the shoots to restrain excessive growth.

Schizophragma hydrangeoides is sufficiently frost-hardy (zones 5-8) in the majority of Poland. However, I wouldn’t recommend it to grow in the mountainous zone and the area of the northern-east Poland, as severe ground frosts may damage its foliage.