Hydrangea macrophylla ‘Nigra’ (syn. ‘Mandshurica’) – This Blackstem Bigleaf Hydrangea is a Chinese cultivar with dark purplish to near-black stems as its claim to fame. These are nicely contrasted by 6-8″ wide bright pink (may be bluish in acid soils) flowers starting in late June and mid green foliage. An RHS Award of Garden Merit winner. Grows 4-6′ high and wide. Zone 6.
Hydrangea macrophylla ‘Firelight’ (syn. ‘Leuchtfeuer’) – A hard to find Mophead Hydrangea with 8″ wide red to bright rose pink blooms (depending on soil pH) starting from midsummer. ‘Firelight’ tends to grow best with some midday shade, but still needs at least 4 hours of direct sun to flower well. Prune when the flowers fade. Grows 4-5′ high and wide. Hardy to zone 6.
Hydrangea macrophylla PISTACHIO (syn. ‘Horwack’) – This reblooming-type hydrangea flowers on both old and new wood. Part of the Forever and Ever Series, it features unusual blooms of scarlet with a deep green tinge from midsummer until frost. It is also a compact shrub with strong stems, and hardier than most Hydrangea macrophylla. Grows 2.5-3′ high by 3-5′. Zone 5.
Hydrangea macrophylla ‘Madame Emile Moulliere’ – This RHS Award of Garden Merit winner is a great choice for an Alba garden. It features ball-shaped blooms of pure white (tinged green as they emerge and occasionally tinted pink in full sun exposures) fringed florets. It does not change colour with the soil pH. Grows 5-6′ high by 4-5′ wide. Hardy to zone 6.
Hydrangea macrophylla ‘Teller Red’ (syn. ‘Fasan’) – The ‘Teller Red’ hydrangea doesn’t have your typical mophead flower, but features very large plate-like lacecap blooms with a ring of large sterile florets on the outer edge and tiny fertile flowers in the center. It blooms from July to August and makes an excellent cut flower. Grows 5-6′ high by 5-6′ wide. Hardy to zone 6.