Hydrangea macrophylla 'Nigra'Hydrangea macrophylla 'Nigra' Black Stem Mophead Hydrangea A beautiful heritage hydrangea cultivar with distinctive slender black stems, which add interest even when Nigra is not in flower. Flower heads are large and rounded, with a charmingly untidy arrangement of blooms that are light rose pink in alkaline soils, or light blue in acidic soils. Sepals are entire. Flowering time is from January to March. This frost tolerant shrub is deciduous, with