Hydrangea heteromalla Bretschneideri

Hydrangea heteromalla Bretschneideri is a superb hydrangea that is robust, hardy, low maintenance and very ornamental, yet remains little used in our gardens. This large shrub with a broad habit has very beautiful green leaves that blaze in autumn and a generous summer flowering in fluffy and flattened inflorescences, which turn from white to pink and remain decorative for a long time. This species with its wild charm should be reserved for large spaces and used as a backdrop due to its impressive presence, accommodating character and ease of cultivation in ordinary (albeit not overly dry) soil.

Originally from the Himalayas and spread across an area ranging from Nepal to northern India, Hydrangea heteromalla is a wild, open-forest species that also appreciates mountain slopes and can climb up to 2000 m (6561 ft) in altitude. It is a large shrub that needs light and a minimum of sun to flower well. It withstands both cold (-20 °C (-4 °F)) and heat (in a more shaded situation). It belongs to the Hydrangeaceae family and is a close relative of the large-leaved hydrangeas and ball inflorescences that no longer need to be introduced.

Hydrangea heteromalla Bretschneideri forms over time (its growth is slow) a very beautiful shrub with a bushy habit, supported by erect main branches bearing more flexible and slightly arched secondary branchess, responsible for its rounded and spread-out, sometimes a little irregular, silhouette. When mature, it will reach between 3 and 5 m (9 ft 10 in and 16 ft 5 in) in height for 2 to 3 m (6 ft 7 in to 9 ft 10 in) in span. This hydrangea develops many ramified branches. Its bark, initially villous, peels off over time, becoming almost corky and grey-brown in colour. In autumn, the leaves fall and create a rather decorative scene which is to be enjoyed. The flowers, abundant and very long-lasting, usually appear between the end of June and August, on the branches of the previous year. In this variety, the inflorescence, or corymb, is flattened and 15 to 25 cm (5.9 to 9.8 in) wide. It consists of sterile florets with four white petals, few in number, forming an irregular and very sparse crown around the smaller fertile flowers. These, much more numerous and similar to small buds, then bloom into tiny white flowers with prominent stamens. After pollination by insects, the fertile flowers often turn pink. This particular flowering more closely resembles that of some Viburnums (Viburnum sargentii, V. plicatum, etc.) than the classic Round-headed Hydrangeas (Hydrangea macrophylla). Combined with its broad habit, it gives this Hydrangea a very natural and slightly romantic appearance.

Its foliage also contributes to the appeal of this shrub. It is composed of ovate leaves 10 to 15 cm (3.9 to 5.9 in) long, carried by a bright red petiole 3 to 4 cm (1.2 to 1.6 in) long. They are slightly villous, quite dark green on the top, almost white on the underside and marked with quite deep veins. This foliage, deciduous in winter, tinges more or less red during the summer (depending on exposure), then turns orange and purple in autumn before falling.

This magnificent shrub, once well established, requires very little care except for regular watering in case of a dry summer. It likes light shade or semi-shaded environments, but it is one of the few hydrangeas, along with Hydrangea quercifolia and H. aspera sargentiana, to show tolerance towards the presence of limestone (without excess) in the soil. Naturally, it will also enjoy a heath soil bed where you can plant it in the background with shrubs whose flowering periods are offset from its own, in order to enjoy staggered blooming. For the beginning of the year, choose the amazing Hamamelis with their incomparable yellow, orange or red flowers. Then a Magnolia Genie will enchant the spring with its wine-coloured flowers, followed by Enkianthus with its delicate and romantic bells. Summer will be the prime season for our Hortensia Bretschneideri, whose flowering can be extended by that of its cousin, the original Hydrangea macrophylla 'Light'o'Day'. And, to finish off the year, an Autumn Camellia will be perfect to conclude this round of flowering.