Why are Hydrangea Flowers Turning Green?

With showy blossoms in pink, lavender, blue, white and cream, hydrangeas are an instantly recognizable plant. Inexperienced gardeners are often taken by surprise when their otherwise colorful hydrangea flowers turn green.

If this is something that has happened to your hydrangeas, don’t worry there are a few sensible explanations to why that might have happened.

Below I’ll explain how soil, light, moisture and aging can all cause hydrangea blooms to turn green. But there are also green hydrangea varieties that will always put out green blooms. I’ll cover those too.

Hydrangea Blooms Change Colors

You probably know by now that hydrangeas prefer slightly acidic soil. The acidity of the soil can trigger a color change in hydrangeas, turning pink blooms blue or blue blooms into pink.

White hydrangeas don’t usually have the ability to change colors, although some white or cream varieties can turn to shades of pink.

It is believed that colorful hydrangea blooms can fade to green when aluminum in the soil is depleted. Adding aluminum sulfate can help control the color of your hydrangeas. But this is only one possible explanation.

Another explanation is simply that as blooms age, they naturally fade to green. This can be explained by changes in light levels throughout the season and how light interacts with the pigments that are responsible for the color of hydrangea flowers.

When days are long and there’s plenty of sunshine, color pigments have energy reserves necessary to dominate. When lights get shorter and there’s less sunshine, the color pigments that make up pink, blue and lavender blooms will fade away and turn green.

Another thing that can influence this process of colors fading from hydrangea blooms is the moisture level of the soil. To stop bloom colors from fading and turning green, you must maintain a good moisture level in the soil.

Whenever rain is scarce or temperatures are high, you should supplement moisture levels in the soil by deeply watering your hydrangeas.

Besides adequate moisture levels, nutrition is another important factor in maintaining the colorful blooms of your hydrangeas. Fertilizing your hydrangeas will also maintain the vibrancy of the blooms.

Fertilizing Hydrangeas

Hydrangeas benefit from a few applications of fertilizer during the growing season to strengthen the root system, aid in stem and leaf development, and help it bloom better.

You can pick from a variety of slow-release fertilizers, liquid fertilizers, dry or granular fertilizers. Some of these can be applied directly to the soil, others require dilution.

Regardless of which you choose, make sure they’re suitable for hydrangeas and that you follow dosage instructions correctly. Liquid fertilizers and some granular ones may require dilution in water, others can be applied directly to the soil or need to be worked into the soil.

Depending on the formulation, you may need to use the fertilizer once at the beginning of the growing season, 2-3 times a year, or weaker formulations might require weekly or bi-weekly applications.

A good fertilizer for hydrangeas is the one made by Miracle-Gro and formulated for acid-loving plants, including Hydrangeas, Azaleas, Camellias, and Rhododendrons.

It’s a water-soluble, dry fertilizer that’s rich in iron and other nutrients beneficial for acid-loving plants. Dilute it in water and use it in your watering can to fertilize your hydrangeas.

The formulation of this Miracle-Gro plant food enhances the vibrancy of foliage and blooms. Use 1 tablespoon of Miracle-Gro for every gallon of water and soak the base of the plants. Feed every 1-2 weeks.

Don’t add more fertilizer than what’s recommended by the manufacturer, otherwise you risk causing fertilizer burn.

Green Hydrangea Varieties

When hydrangeas turn green, they may keep on blooming green for the entire season. Sometimes, they may continue blooming green for a second season too before they revert back to their normal colors.

Some hydrangeas routinely produce green blooms because of their variety. These cannot have colorful blooms to begin with, and they’ve been selectively bred for green blooms. The blooms usually start out white, then turn green and end in white as they age.

Here are some hydrangea varieties that produce green blooms:

  • Limelight hydrangea
  • Annabelle hydrangea

You can see green hydrangeas in many floral arrangements and wedding bouquets as they provide a good backdrop for other plants and flowers.

At the end of the day, a hydrangea with green blooms isn’t something to be worried about. It’s a natural process and should not be treated as a pathological condition.

You can make some changes in the environment of your hydrangea to try to prolong the lifespan of colorful blooms, but since you can’t control the weather and outdoor light conditions, there’s no shame in letting nature take its course and hope the blooms will come back in the original colors the next season.

Do You Deadhead Green Hydrangea Flowers?

Deadheading hydrangeas promotes bigger and more vibrant blooms. If your green hydrangea blooms have wilted, you can go ahead and remove them.

If you’re thinking about deadheading green hydrangea flowers hoping they’ll come back in their original pink, blue or lavender, you can, but since hydrangea blooms turning green seems to be a seasonal thing, I’m not sure you’d be successful in your endeavor.

I usually wait for green blooms to fade and only then do I deadhead them. Honestly, I don’t mind if my hydrangea blooms turn green.

Keeping up a good plant care regimen, looking out for good nutrition and soil acidity are things you can do to minimize the risk of green blooms.

Ultimately, however, you cannot compete with changing light conditions, and despite your best efforts, hydrangeas can still put out green blooms.

Wrapping Up

Now that I’ve discussed some of the possible causes of green blooms on pink, lavender, blue or cream hydrangeas, you can take some measures to extend the lifespan of these colorful blooms.

Don’t get discouraged if your hydrangeas don’t return to their original colors. Your hydrangea will produce colorful blooms again in a season or two. Until then, you can still propagate your hydrangea plant and enjoy colorful blooms.

Hydrangeas   Updated: June 6, 2022
avatar Hi, I'm Amy, a devoted horticulturist and the creator of PlantIndex.com, where I use my expertise to help beginners foster their green thumbs. My blog is a vibrant community where I unravel the complexities of gardening and share my profound love for nature.
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