Hydrangea macrophylla Nigra

The Hydrangea or Hydrangea macrophylla 'Nigra', as its name suggests, stands out for its black wood. This enticing plant is a relatively compact and nicely rounded bush, with very dark stems and lush fir-green leaves, on which beautiful pale pink or soft blue flowers rest throughout the summer, depending on the nature of the soil. This hardy little bush will also draw attention in winter. It fits just as well in neat small gardens as on a terrace with a contemporary decor, to brighten up a shady area, in fresh and non-limestone soil.

The Hydrangea macrophylla 'Nigra' (synonym Hydrangea macrophylla 'Mandshurica') was introduced to the market in 1993,  by the National Arboretum of the United States. It comes from the species H. macrophylla, native to Japan. Hydrangeas belong to the Hydrangeaceae family. 'Nigra' is part of a series of cultivars selected for their dark stems, covered with a young bark of almost black purple. This bush shows a bushy and rounded habit, regular, elegant. At the age of about 10 years it should grow to the size of 1 m (3 ft 4 in) 50 high and 1 m (3 ft 4 in) 20 wide. It produces large, dense spherical flower heads from July to September-October, at the end of long black stems aged 1 year or more. They are composed of a few rare fertile flowers and many larger sterile flowers, with striking dimorphism. In acidic soil, the flowers take a pale blue hue at maturity, in neutral soil they will be soft pink. The flowers change colour over time, fading to pretty shades of green, red, beige or brown. The flowering spreads over a lush shiny dark green, dentate, deciduous leafage. The leaves are opposite, they reach a minimum of ten centimetres in length. They are single, ovate to elliptical, ending in a pointed tip, roughly serrated. Hydrangeas can live at least 50 years.

The Hydrangea 'Nigra' is a structural plant, with an elegant and assertive personality, a bush to highlight parts of the garden or to dazzle in a large pot on the terrace. Hydrangeas are well known for brightening up the north side of houses. This variety will be happy with a non-burning east or west exposure, in semi-shade, planted in a border or as a standalone shrub. This variety is suitable for container cultivation, which will be positioned on the terrace in a large pot, or near the entrance. Eventhough these plants are not fond of limestone, they are not strictly speaking ericaceous plants. Combine hydrangeas with each other, with magellanica fuchsia, silver candelabras, Physocarpus, Japanese azaleas, annual impatiens, lilies, or plant spring-flowering bulbs in front of their round silhouette. Enjoy their sumptuous flowering in the garden or in the house.

Note: The colour of the flowers of macrophylla hydrangeas varies according to the PH of the soil. Traditionally blue varieties become pink in neutral or alkaline soil. To maintain a beautiful blue colour, mix ericaceous soil with your garden soil and add aluminium sulphate (slate contains it) or alum stone in spring.