Hydrangea flowers commonly change colors as they dry and age on the plant. Some varieties even turn a striking shade of green. These green hydrangea flowers are often used to create decorative dried arrangements. Not all hydrangea varieties turn green, but the ones that do can vary in color from pale, lime green to deep blue-green.
The hydrangea flower is actually a flower head. Each flower head is made up of multiple small blooms clustered together to create a pompom shape. The size of the flower head depends on the variety. Some hydrangeas produce flower heads up to 7 inches (about 17 cm) in diameter.
Green hydrangea flowers develop from several different varieties. Some hydrangeas never turn green at all. Hydrangea macrophyllia is one variety that can develop green flowers. For a hydrangea that turns reliably green, the Annabelle hydrangea is one of the best varieties to grow.
Hydrangea macrophylla, commonly called florist's hydrangea or French hydrangea, is a commonly cultivated variety that develops green flowers towards the end of the growing season. When first in bloom, the flowers are either pink or blue, depending on the levels of aluminum in the soil. Once the flowers begin to dry, they turn shades of green. As they continue to dry, either on or off the shrub, pink and blue shades can reappear.
Annabelle hydrangeas have snowy white flower heads that turn lime green as they dry. Once the flowers turn green, they remain green throughout the drying process. When growing Annabelle hydrangeas in the garden, the shift from white to green can typically be observed toward the second week of the blooming process.
The best way to produce a green hydrangea is to allow the flower head to dry on the plant. As the flowers wither, they develop a papery feel and appearance. A pair of sharp pruning shears can then be used to harvest the dried flower heads. While it is important to leave the hydrangea flowers on the shrub until almost completely dry, a spell of rainy or windy fall weather can have a devastating effect on the dried flowers. Better to harvest early when foul weather threatens than to lose the green hydrangea altogether.
The green hydrangea flowers sold by retailers are usually always dried. White dried hydrangea flowers may also be dyed green with artificial dyes. Very occasionally, a hydrangea plant might produce fresh, green flowers for a season, but this is not common and typically not consistent.
