Chances are, you saw the name of this article and thought, “Don’t you want your Hydrangeas to be nice and green?” But we’re not talking about growing green Hydrangea foliage.
Instead, certain conditions in which your hydrangea flowers will also turn green.
Unlike hybrids such as particular tea roses bred for green blooms, having a hydrangea turning green when it should be another color can cause alarm.
Why Are My Hydrangeas Turning Green?
The good news is there are 5 potential reasons for your hydrangea blooms to turn green, and none threaten the plant.
Let’s take a look at the two times this is perfectly normal and three times when environmental conditions can cause the change.
If you’ve had hydrangeas before, you’ll know that some blooms change color as they age.
Pink or blue flowers often turn green at the end of the growing season, although this can also happen with other colors.
In these cases, the green tends to be an underlying hue that becomes apparent as the blooms fade before they begin to turn brown and wilt. A brown Hydrangea is not pretty!
In some cases, the green blooms may later exhibit undertones of pink or burgundy.
- For reasons we don’t understand, a hydrangea sometimes gets “stuck” after the first blooms turn green.
- In such instances, the remaining blooms throughout the season will be green from start to finish.
- This can even carry on through the next season, with the original bloom colors only returning after this period.
- However, rest assured that the blooms will eventually regain their original coloration.
While the exact reasons for this are unknown, it’s clear that high temperatures, weather conditions, and high humidity can turn blooms green.
This is most often seen in the southernmost zones but can also happen further north during muggy heatwaves.
One popular theory is that the roots are under stress, and the added humidity is causing the colorful flowers to turn green or brown prematurely.
When hydrangea is under stress, its root system cannot draw up moisture to replace the leaf moisture loss.
Ensuring the plant has consistently moist soil can help alleviate the stress to some degree.
As a side note, in cooler climates, many cultivars will turn beautiful shades of blue and purple instead of green.
This environmental factor deserves its own section because it’s easy to screw things up if you try to fix what isn’t broken.
After Midsummer, the days begin to grow shorter, and the amount of light also diminishes.
This process is perfectly natural, although your hydrangea blooms may begin to turn green.
Again, this is a natural process, and you shouldn’t worry if your plant thrives throughout the summer months.
However, if the plant lacks full sun during the summer and shows other signs, you can transplant it to somewhere sunnier.
Generally, hydrangeas need at least 6 hours of sunlight daily.
Just keep in mind that there are varieties of hydrangea that prefer a little light afternoon shade and can be scorched if moved.
This is why it’s essential to learn about the care needs of each specific cultivar, as they can have variations in behavior, care needs, and other aspects.
Hungry Hydrangeas – Malnutrition
Hydrangea blooms can turn green when they’re not getting enough nutrients.
Using a liquid-soluble fertilizer can make it much easier to ensure your plant is getting the right amount of each nutrient, as granular, time-release formulas won’t dissolve evenly.
Try to go with a slightly acidic mix, and don’t be afraid to start with a formula with higher nitrogen, then switch to a higher phosphorus mix when the first blooms are ready to appear.
A slightly acidic pH is vital for hydrangeas, and one theory behind green blooms is that the soil isn’t acidic enough.
Remember, changes in soil acidity can cause a change in the color of hydrangea blooms. Acidic soils lead to blue hydrangeas, while alkaline soils make pink hydrangea flowers.
Another theory is a possible aluminum deficiency, and adding a bit of aluminum sulfate to the soil seems to help preserve the bloom color a while longer.
Even if your plant’s blooms turn green naturally due to age, proper nutrition can help you retain their original colors longer.
To maintain the healthiest shrubs, investing in a soil test every 3 to 5 years is never a bad idea.
Not only will this tell you the pH and what nutrients are missing, but it can also tell you when the soil has too much of a nutrient so you can adjust your fertilizer to match.
Finally, let’s talk about hydrangea cultivars created specifically to produce green hydrangea blooms.
One example is Hydrangea paniculata ‘Limelight,’ which produces green flowers and stays lime green throughout the season.
Annabelle and Limelight hydrangeas were created specifically to turn from white to green as they age.
These blooms are popular in wedding bouquets and other arrangements.
The color change usually happens around 2 weeks into bloom.
Should I Deadhead Green Blooms?
This is honestly a matter of personal preference.
Pink or blue blooms that fade to green can be deadheaded to encourage fuller blooms.
However, you may also wish to leave the green blooms as a pleasant contrast to your hydrangea blossoms.
They can also be clipped for a vase since the green blooms still have some life.
You can also apply garden lime to raise the soil pH levels and your desired hydrangea color transition.