Cardinal Red Hydrangea ShrubsCardinal Red Hydrangea Shrubs for Sale Online Cardinal Red Hydrangea Shrubs are a French type, mophead Hydrangea that actually produces dark, pink flowers with serrated edges on each petal. Flowers are a standout in partially shaded areas of the garden during summer and can then be cut and dried for use in dried flower arrangements. This flowering shrub starts out light pink when it first blooms, then transitions to deep cardinal red as the plant