How to Propagate hydrangea 'Cardinal Red'?
Propagate by softwood cuttings in early summer, or by hardwood cuttings in winter

hydrangea 'Cardinal Red' · Hydrangea macrophylla 'Cardinal Red'
Grow in moist but well-drained, humus rich soil, in a lightly shaded spot with shelter from cold, drying winds. Mulch annually in spring. Soil additives may be required to maintain specific flower colours. See shrubby hydrangea cultivation for more detailed advice
Propagate by softwood cuttings in early summer, or by hardwood cuttings in winter