Dahlia ‘Dinnerplate Manhattan Island’ is an impressive dinnerplate dahlia known for its enormous, show-stopping blooms and vibrant, rich red color. The plant forms strong, upright stems with dark green, pinnate leaves, providing a sturdy framework for its massive flowers. Each bloom can reach 20–30 cm (8–12 in) in diameter, with tightly packed petals that create a dramatic, layered appearance. Ideal for garden beds, borders, or as a striking cut flower, this variety adds bold color and visual impact to summer and early autumn gardens.
- Size: Height: 90–120 cm (3–4 ft). Spread: 60–90 cm (2–3 ft).
- Flowering: Mid-summer to first frost
- Growth habit: Upright clumping perennial from tubers
- Light: Full sun for best flowering and strong stem growth.
- Soil: Well-drained, fertile soil enriched with compost; avoid soggy conditions.
- Water: Regular watering; keep soil evenly moist but not waterlogged.
- Hardiness: Hardy in Zones 8–10; in colder climates like Regina, SK, tubers must be lifted and stored over winter.
- Planting depth: Plant tubers 10–15 cm (4–6 in) deep, spacing 60–90 cm apart.
- Maintenance: Stake stems early to support large blooms; deadhead spent flowers to prolong flowering.
- Propagation: By tuber division in spring before planting.
- Pests/Disease: Watch for aphids, slugs, and powdery mildew; ensure good air circulation to reduce disease risk.