Why Hydrangea Flowers Turn Green and How to Manage Bloom Color

Green Blooms: Natural Aging

Hydrangea flowers (especially in the South) naturally turn green as they age. This is not a nutrient deficiency—it's the normal life cycle of the sepals.

Color Change Timing

• Soil pH adjustment: Apply aluminum sulfate (for blue) or lime (for pink) in May and July in the South, July only in the North.
• Changes take months; affect next season's blooms.

Deadheading

• Remove spent blooms to keep plants tidy.
• Or leave dried heads for winter interest and arrangements.
• Cut just above the first set of large leaves.

Reference

Excellent resource: HydrangeasHydrangeas.com