If you are a Hydrangea fan, you must have heard the name Smooth Hydrangea. But what is Smooth Hydrangea and how I can distinguish it from other types? Although Hydrangeas are known for their incredible blooms, their various types such as Smooth Hydrangea are classified based on their leaf’s characteristics.
Hydrangea plants belong to different botanical species. Some sources say there are 23 species in this genus, while others believe there are 49 or even 80. However, there are, only 6 types commonly grown in American gardens: Smooth, Big Leaf, Climbing, Mountain, Panicle, and Oakleaf.
In this article, I will discuss Smooth Hydrangea, so, Keep reading to tell you more about this stunning flowering plant.
Smooth Hydrangea: A Unique Beauty for Your Garden
Smooth hydrangea (Hydrangea arborescens) is a deciduous shrub native to the eastern United States. It’s known for its large, rounded clusters of white flowers that can grow up to 12 inches in diameter. I recommend reading my other post “Plants with clusters of white flowers” too. Unlike other hydrangea species, the colour of its blooms is not influenced by soil pH, making it a reliable choice for gardeners.
Why Is it Called Smooth Hydrangeas?
The name “smooth hydrangea” comes from the texture of its leaves. Unlike many other hydrangea species with rough or hairy leaves, the leaves of smooth hydrangea are smooth to the touch, hence the name. This distinctive leaf texture is one characteristic that helps differentiate smooth hydrangea from other hydrangea species.
Other Key Differences of Smooth Hydrangea from Other Hydrangeas
In addition to their leaves, here, I listed some features of Smooth Hydrangea:
- Flower Color: While many hydrangeas can change colour based on soil acidity (pink in acidic soil, blue in alkaline soil), smooth hydrangeas primarily produce white flowers. However, recent cultivars have been developed with pink and even purple blooms.
- Bloom Shape: Smooth hydrangeas typically have a rounded or domed shape to their flower clusters, whereas other species might have more conical or lacecap-shaped blooms.
- Bloom time: June to September. you can find 6 eye-catching endless summer hydrangea varieties for 2025 in my other post.
- Growth Habit: Smooth hydrangeas tend to be more compact and bushier in their growth habit compared to some other hydrangea species. It blooms on new growth.
- Height/Spread: 3-5 feet/3-5 feet
- Hardiness: 3-9. They are generally considered very hardy and can tolerate cold climates. However, they may die on the ground in harsh winter. Smooth hydrangeas are intolerant of drought.
- Light Requirements: Part shade. Full sun only in consistently moist soil.
- Pruning: Prune close to the ground every other year in late winter to keep neat and encourage new growth.
Popular Cultivars of Smooth Hydrangea
- Annabelle: A classic variety with large, pure white blooms.
- Invincibelle Spirit: Known for its vibrant pink flowers.
- Pink Annabelle: Similar to Annabelle but with pink blooms.
Smooth hydrangeas are versatile additions to gardens. They offer a low-maintenance and attractive flowering shrub, and their unique characteristics make them a standout choice for many gardeners. If you think Hydrangea is expensive, don’t worry—I listed a cheaper alternative in my other post. I also recommend reading my other post “What to Plant with Hydrangeas in Pots?”
Conclusion
What is a Smooth Hydrangea? It is a popular type of Hydrangea known for its stunning large, rounded clusters of white flowers. Its naming (Classification) is because of the Smooth texture of its leaves to the touch. If you have any questions, please ask me in the comments below. I will answer as soon as possible.
Elahe Rabiei
Hi, I’m Elaheh. My Academic major is plant protection, and houseplants are my expertise. As a houseplant lover, my house is full of indoor plants and it is my passion to take care of them. Hence, I’m here to share my knowledge and experience about growing healthy houseplants. I am also a plant protection advisor, so feel free to ask me any questions you may have.