Strongly branched deciduous shrub. Stem color of new growth blackish purple making a striking contrast to the leaves. Hydrangea macrophylla grows best in moist, well-drained soil, in full sun to partial shade. In the Washington, DC, area, 'Nigra' seems to perform best in moist soil under light shade. Prune immediately after flowering.
Flower color is blue in acid soil and rose-pink in a neutral or slightly alkaline soil.
Will root from cuttings taken at most times of the year.