Common name: None
These are verygrown principally for their large showy . There are several types: the common ‘Mopheads’ and equally attractive ‘Lacecaps’, together with others of upright or climbing habit.
Popular species and varieties
There are many ‘Mophead’ varieties (Hortensias), so which you grow is a matter of personal choice. One with a rather formidable name is ‘Generale Vicomptesse de Vibraye’ (AGM), noted for its early, free-flowering habit. The flowers are pale blue or pink. ‘Niedersachsen’ follows close behind, a vigorous grower ‘Deutschland’ is a rich pink or light blue.
Many have blue flowers when grown in acid conditions, and are pink when grown in alkaline soils. The whites are unaffected, remaining constant especially when grown in light shade; they will take on a reddish tinge if planted in a sunny spot ‘Lacecap’ varieties to look out for are ‘Blue Wave’ (AGM) and the lovely white ‘Lanarth’, which has neat, compact growth.
The climbing hydrangea is H. petiolaris (AGM), a vigorous self-clinging deciduous shrub which can, in ideal conditions, reach 20m (60ft) or more, producing flattened clusters of white flowers in late spring. It is no stranger to Western gardens having been introduced from the Far East in 1865.
One more species is the oak leaf hydrangea (Hydrangea quercifolia) (AGM). This produces long white flowers, at first creamy-white, taking on a pinkish tinge as they age. The US-bred ‘Snow Queen’ is the one to look for; a large-flowered choice with upright panicles over bushy growth.
Soil type Humus-rich, well-drained. As already seen, soil conditions affect the flower colour.
Planting Select a sheltered position in a lightly shaded spot. Avoid areas where there is early morning sun after late frost as this can damage new growth. Plant in the autumn or spring. The climbing hydrangea can take two or three years to become established.
Maintenance Pruning is not required. Flowers of ‘Mophead’ hydrangeas should not be removed until late winter. Not only are they still attractive in the winter months, but they also provide shelter for new, young growth. In the case of ‘Lacecaps’, remove the dead-heads immediately after flowering. If you wish to cut back any straggly branches, this should also be done in late winter.
Propagation Semi-ripe cuttings of around 15cm (6in) in length, taken from non-flowering shoots.
Pests and Diseases Aphids can attack young growth in the spring.