Hydrangea 'Deep Purple Dance' purple - Hardy plantLarge and colourful. This perfectly describes the hydrangea 'Deep Purple Dance' (Hydrangea macrophylla). The bush has purple flowers you can enjoy for months. The flowers bloom from summer to autumn. Pruning is not necessary, unless the bush becomes too large. Plant the hydrangea in partial shade. The soil should be kept damp. Give it extra water during dry periods.