Bigleaf Hydrangea 'Pistachio': Unique Bicolor Blooms in Green and Red

Bigleaf Hydrangea 'Pistachio': A Color Combination Like No Other

Hydrangea macrophylla 'Pistachio' (PPAF, also known as 'Horwack') stops visitors in their tracks with its extraordinary bicolor flowers: each sterile floret is a striking combination of pistachio green and rich red, creating a look unlike any other hydrangea. This recent introduction brings truly novel coloration to the mophead class.

Unprecedented Bicolor Effect

The mophead inflorescences are large, 6–8 inches across. Each sterile floret emerges pale green, then develops a vivid red margin and central eye, while the base remains pistachio green. The result is a flower head that appears simultaneously green and red—a mesmerizing, almost artificial-looking combination. As the flowers age, the green deepens and the red intensifies, eventually shifting to antique burgundy and olive.

The plant is compact, 2–3 feet tall and wide, with strong stems and dark green foliage.

Cultivation

Morning sun or bright shade, consistent moisture, rich well-drained soil. Hardy in USDA zones 5–9. The bicolor pattern is genetically fixed and not significantly influenced by soil pH (though the red intensity may vary slightly). Blooms on old wood. A relatively new introduction (PPAF = Plant Patent Applied For at time of listing).

Taxonomic Profile

• Family: Hydrangeaceae
• Genus: Hydrangea
• Species: macrophylla
• Cultivar: 'Pistachio' (PPAF; syn. 'Horwack')

Conversation Piece

'Pistachio' is a guaranteed focal point and conversation starter. Its bizarre, beautiful coloration defies expectations. Use as a specimen in a prominent location, in a container where it can be appreciated up close, or in a cutting garden for truly unique arrangements. A cultivar that expands the color palette of hydrangeas into entirely new territory.