25 Fun and Interesting Facts About Hydrangeas

Written by Alanna Davis
Published: March 2, 2024
Share on:


Hydrangeas can be a divisive flower; many people either adore them or dislike them entirely. Despite this, there’s no denying that they’re some of the most iconic blooms of all. Hydrangeas have become popular across the globe and can be found growing on nearly every continent. Let’s dive into 25 fun and interesting facts about hydrangeas!

1. There Are Roughly 75 Different Species of Hydrangeas

Despite this large number, only a handful of hydrangeas are commonly grown in gardens.

©qiufan bu/Shutterstock.com

According to North Dakota State University, “The Hydrangea (or Hortensia) genus consists of about 70-75 species and over 600 named cultivars.”

2. Hydrangeas Come In a Variety of Different Colors

Hydrangea flower garden

Hydrangeas range in shades from vibrant pink to deep blue.


Believe it or not, the pH level of the soil that hydrangeas are planted in will play a huge role in determining their color.

3. Many Hydrangeas Are Native to Asia

Hydrangeas are beloved across the globe.

©iStock.com/Marketa Bement

Some Asian hydrangea varieties include ajisai, Chinese hydrangea, and climbing hydrangeas.

4. The Word Hydrangea Has Greek Origins

Hydrangeas are sometimes called “change roses.”


The word “hydrangea” is a combination of the Greek word “hydros,” meaning water, and the Greek word “angos,” meaning vessel. These words combine to create something similar to “water vessel,” nodding to this plant’s voracious appetite for water.

5. Hydrangeas Are Cape Cod’s Signature Flower

Cape Cod hosts an annual hydrangea festival.

©Janice Higgins/Shutterstock.com

Even though hydrangeas aren’t native to Cape Cod, they’ve exploded in popularity here. So much so that this flower is an absolute symbol of this area.

6. Hydrangeas Are Toxic

If your pet or child accidentally consumes hydrangeas, seek medical attention immediately.

©iStock.com/Maryna Andriichenko

Despite their beauty, this flower is dangerous. If ingested by humans or animals, it can be potentially deadly as it contains trace amounts of cyanide.

7. Hydrangeas Have a Long Blooming Season

If the temperature outside gets too hot, hydrangeas may stop blooming.

©Joanne Strell/Shutterstock.com

Hydrangeas bloom for a very long time in many regions in the United States, typically starting in March and ending in October. Depending on where you live, this will vary slightly.

8. Hydrangeas Can Have Many Different Meanings

Gifting hydrangeas is common in many places throughout the world.

©Nguyen Minh Tam/ via Getty Images

While some cultures see these flowers as a symbol of arrogance, others interpret hydrangeas as embodying positive qualities, such as new beginnings, innocence, and gratitude.

9. Hydrangeas Don’t Really Have Petals

The sterile flowers are highly visible while the fertile flowers are less pronounced.


Although it might be surprising, those delicate flower petals aren’t actually petals at all. According to the Norfolk Botanical Garden, “The flowers do not have petals, but the sterile flowers have developed very showy sepals (part of the outer portion of a flower known as the calyx).”

10. Hydrangeas Have Their Own Holiday

The amount of people who celebrate National Hydrangea Day increases each year.


Individuals who are passionate about this flower will be happy to learn that it has its own dedicated holiday. National Hydrangea Day is celebrated on January 5th each year.

11. Hydrangea Enthusiasts Have Their Own Club

Woman holding large bouquet of hydrangeas, roses

Hydrangeas make a perfect addition to any bouquet.

©Mila Naumova/iStock via Getty Images

Are you a hydrangea fanatic? If so, you’re in luck because the American Hydrangea Society is accepting new members!

12. Hydrangeas Are the Perfect Flower for Individuals With Allergies

In addition to being allergy-friendly, hydrangeas are also easy to grow.

©Michele Dorsey Walfred / Flickr - License

Unlike other flowers, the pollen that hydrangeas produce is sticky and not easily carried by the wind. Because of this, many people with allergies report that this flower doesn’t trigger them as much as others.

13. Hydrangeas Are Hardy

Hydrangeas grow well in zones three to nine.


If you’re not someone who has a green thumb, hydrangeas just might be the flower for you. These plants are hardy to a variety of weather and temperature conditions.

14. Some Hydrangeas Can Grow To Be Over 50 Feet Tall

Hydrangea petiolaris blooming. Young green leaves of Hydrangea petiolaris in summer. Climbing Hydrangea

Some climbing hydrangeas can reach 80 feet tall.

©Mikhail Kolomiets/ via Getty Images

Although some hydrangeas are small, other species, such as the climbing hydrangea, can grow to incredible heights.

15. French Hydrangeas Are the Most Popular Variety

Hydrangea changeable large-leaved Garden French wild-growing bush. Variety of paniculate and tree-like hydrangea. Blue and pink flowers

Hydrangeas will bloom yearly.


Although many different hydrangeas are easy to care for and beautiful, the French hydrangea takes the title of the most popular choice.

16. The Color of a Hydrangea Can Change Its Meaning

An ornamental garden filled with colorful hydrangea blossoms.

Gardeners can control the color of their hydrangeas by altering the pH level of the soil.

©iStock.com/Cheryl Ramalho

Some people believe that pink hydrangeas symbolize romantic love, while blue hydrangeas symbolize sorrow or forgiveness. White hydrangeas usually carry the meaning of innocence and purity.

17. A Hydrangea Is the State Wildflower of Alabama

Similar to other hydrangeas, the oak leaf hydrangea comes in a variety of colors.


In 1999, the oak leaf hydrangea was declared the state wildflower of Alabama.

18. Hydrangeas Are Perennials

A closeup of hydrangea blue deckle flowers

The correct hydrangea variety for your zone is a key part of them coming back each spring.

©Light and Vision/Shutterstock.com

If gardeners take care of their hydrangeas, they will return each year as they are perennials.

19. Hydrangeas Are a Popular Anniversary Gift

These flowers are sure to please as a gift for any occasion!


Some people believe that hydrangeas should be gifted on a couple’s fourth wedding anniversary in order to convey your appreciation for your partner.

20. Hydrangeas Require a Lot of Watering

Beautiful little toddler girl in red colorful dress watering blossoming roses flowers with kids water can. Happy child helping in family garden, outdoors on warm sunny bright day

French hydrangeas in particular need a lot of water to survive.


Although this hardy flower is somewhat low maintenance, watering it properly is key. This will ensure that your plant blooms consistently.

21. Hydrangeas Attract a Variety of Insects

Butterfly stopping on pink Hydrangea.

Lace cap hydrangeas in particular are attractive to insects.


Although this plant might be deadly to animals and humans, it attracts a variety of insects such as butterflies, moths, and bees.

22. Many People Plant Hydrangeas for Privacy

hydrangea tree with pale pink and white blooms

Hydrangeas are functional in addition to being aesthetically pleasing.

©Edita Medeina/Shutterstock.com

Since these shrubs can grow thick and dense, hydrangeas can serve as a beautiful privacy hedge.

23. Hydrangeas Can Live Up to 50 Years

Hydrangeas prefer partial-sun areas.

©Natallia Ustsinava/Shutterstock.com

If gardeners consistently water and properly care for their hydrangeas, they can live for up to half a century!

24. White Hydrangeas Don’t Change Color

White hydrangeas look like large clumps of cotton.


Unlike colored hydrangeas, white hydrangeas don’t change color based on the pH level of the soil that they’re planted in.

25. Hydrangeas Are Ancient

hydrangea in Hase temple, Kamakura

Fossilized flowers are quite rare.

©ziggy_mars/iStock via Getty Images

Hydrangeas are one of the most ancient flowers of all, and some hydrangea fossils have been discovered that date back to roughly 50 million years ago.

The photo featured at the top of this post is © Alya_Ro/Shutterstock.com

Share on:
About the Author

Alanna is a writer at A-Z Animals primarily covering insects, animals, and travel. In addition to writing, she spends her time tutoring English and exploring the east end of Long Island. Prior to receiving her Bachelor's in Economics from Stony Brook University, Alanna spent much of her time studying entomology and insect biology.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.