Hydrangeas, the glory of summer! These full blooming beauties, once relegated to old-fashioned gardens have enjoyed a well deserved resurgence in popularity. While there are many varieties within the species, the large macrophylla or mopheads are still the most popular. While their normal summer-blooming color is blue, pink, or white, we all notice those green hydrangea flowers at some point in the season. Why do hydrangea flowers bloom green? Is there a cause of green hydrangea blooms?
Causes of Green Hydrangea Blooms
There is a cause of green hydrangea blooms. It’s Mother Nature herself with a little help from the French gardeners who hybridized the original hydrangeas from China. You see, those colorful flowers aren’t petals at all. They’re sepals, the part of the flower that protects the flower bud. Why do hydrangeas bloom green? Because that’s the natural color of the sepals. As the sepals age, the pink, blue, or white pigments are overpowered by the green, so colored hydrangea blossoms often fade to green over time.
Many gardeners believe that color is controlled solely by the availability of aluminum in the soil. Aluminum gives you blue flowers. Bind up the aluminum and you get pink. Right? That’s only part of the story. Those green hydrangea flowers turn color with longer days of light. Light gives those colors the energy to dominate. The color can last for weeks and then you find your hydrangea flowers turning green again. The days are becoming shorter. The blue, pink, and white pigments lose energy and fade away. Once again, green hydrangea flowers reign.
Sometimes you’ll find a hydrangea with green flowers all season long. If you’re new to the garden or the plant is new to you and the plant blooms later than its brethren, you might have a variety called ‘Limelight.’ These relatively new plants have much smaller leaves than the big leaf varieties, although their blooms look similar to the mophead hydrangeas. Flowers turning green is natural to this beauty whose blooms begin and end in white but are bred to be green in between those times.
But if your hydrangea with green flowers is any of the other types and the blooms refuse to change, you’re the victim of one of Mother Nature’s occasional pranks and horticulturalists have no explanation for the condition. It may be a combination of unusual weather conditions, but no scientific reason has been found. Take heart. Your hydrangea with green flowers should only suffer the condition for a season or two before the plant returns to normal.
Why do hydrangeas bloom green? What’s the cause of green hydrangea blooms? They’re interesting questions for the curious, but in the end, does it really matter? If you find your hydrangea flowers turning green, sit back, relax, and enjoy the show. It’s Mother Nature at her best.