Are Hydrangeas Annual, Biennial, or Perennials?

Hydrangeas are among the most beloved garden plants, known for their stunning blooms and versatility. Before you make the decision to plant these stunning flowers, one question may occur to you – are hydrangeas perennials? Will they come back each year? Or, you have to replant the seeds every year just to keep the scene. 

The good news is that hydrangeas are perennial plants that come back year after year, as long as you choose the right varieties for your hardiness zone. To expand on the topic and make growing hydrangeas easier for you, we provide you with the following details. 

What Does a Perennial Hydrangea Mean

You may hear a lot about terms like annual, biennial, and perennial, but what exactly does a perennial plant mean? A perennial hydrangea means that the plant lives for more than two years and comes back each growing season from its root system. Unlike annual plants, which complete their plant lifecycle in one year, or biennials, which take two years to complete their lifecycle, perennial hydrangeas regrow and bloom year after year. 

They typically go dormant in the winter and reemerge in the spring, making them a long-term addition to your garden that requires less frequent replanting. Additionally, hydrangeas are classified as woody perennials, which means their stems aren’t as soft and green as those of tender perennials like hostas. Unlike tender perennials, woody perennials don’t die back with frost. Remarkably, hydrangeas can thrive for up to fifty years when properly cared for and exposed to sufficient sunlight.

Hydrangeas Hardiness Zones

What are the best hardiness zones for hydrangea growing? A plant’s hardiness refers to its ability to survive adverse growing conditions, particularly its tolerance for harsh winters. This means that most hydrangeas can withstand cold winters and come back blooming just as beautifully in the next season.

If you are based in the U.S., most hydrangeas are hardy in USDA zones 3-7, but you will find some types that are hardy up to zone 9. Additionally, some varieties actually perform better in colder climates or even in the shade. In Canada, hydrangeas can thrive in various hardiness zones, typically ranging from zones 3 to 9, depending on the species.

Depending on the zone you are in, choose a specific hydrangea variety to enjoy perennial greenery: 

• Bigleaf Hydrangea (Hydrangea macrophylla): Hardy in zones 6 to 9. They may require winter protection in the colder parts of these zones.
• Panicle Hydrangea (Hydrangea paniculata): One of the hardiest species, suitable for zones 3 to 8. It is a great choice for colder regions in Canada.
• Smooth Hydrangea (Hydrangea arborescens): Hardy in zones 3 to 9. This species is adaptable and can withstand colder temperatures, making it ideal for various parts of Canada.
• Oakleaf Hydrangea (Hydrangea quercifolia): Best suited for zones 5 to 9. While it can handle some cold, it thrives better in milder climates within these zones.

Do Hydrangeas Like Sun or Shade

Can hydrangeas grow in full shade? Hydrangeas prefer to grow in locations that receive partial shade to full shade. While they can tolerate some sunlight, too much direct exposure can cause their leaves to wilt and their flowers to fade quickly. Ideally, morning sun and afternoon shade are best for most hydrangea varieties. Additionally, here are some specific considerations:

Partial sun hydrangeas: Most common hydrangeas thrive in this condition. The reblooming Endless Summer Hydrangea series, including BloomStruck, Endless Summer, and Blushing Bride, prefer part shade. 

Full sun hydrangeas: Panicle Hydrangeas (Hydrangea paniculata) such as Fire Light, Limelight, Pinky Winky, and Strawberry Sundae, can thrive in full sun. The new reblooming dwarf series also grow best in full or part sun. Some newer smooth hydrangea varieties, like Incrediball and Invincibelle Ruby, are recommended for full or part sun.