Bigleaf Hydrangea — Growing reference
| Scientific name | Hydrangea macrophylla |
|---|---|
| First harvest or flowering (days) | 365–730 |
| Measured from | Transplant |
| Plant spacing (cm) | 121.9–182.9 |
| Mature height (cm) | 91.4–182.9 |
| Mature spread (cm) | 121.9–182.9 |
| USDA hardiness zones | 5–9 |
| Light | Partial sun |
| Water | Moderate |
| Sowing method | Transplant |
Growing directions
Plant in moist, humus-rich, well-drained soil in morning sun with afternoon shade; bigleaf hydrangeas are the classic summer-blooming shrubs with large mophead or lacecap flower clusters in blue, pink, or white. Flower color depends on soil pH — blue in acidic soil (pH below 5.5) and pink in alkaline soil (pH above 6.5); to maintain blue, add aluminum sulfate and maintain pH below 6.0. In the South (zones 8–9) afternoon shade is essential to prevent wilting and maintain flower quality. Old-wood bloomers (most classic varieties) should be pruned only immediately after flowering — never in fall, as this removes next year's buds. Reblooming types such as 'Endless Summer' bloom on both old and new wood, making them more reliable after hard winters.
Source and local conditions
Typical planning ranges from OpenPlantDB (CC0). Cultivar, climate, season and growing method can change these values. Confirm the seed label and local guidance before planting.
Source & verification
OpenPlantDB · CC0