How to Identify Types of Hydrangeas (& Know When To Prune)

Use these tips to identify your hydrangea and know when or if it should be pruned. With six main varieties available, these photos will help determine what you are growing.

If you want to propagate your plant, see this tutorial on growing hydrangea from cuttings.

---

What Kind of Hydrangea is this?

There are 49 species of hydrangeas but just six types are commonly grown in Canada and the United States. The ones you see here are courtesy of Proven Winners.

Once you know which variety you are growing, you will know when or if to prune. Contrary to popular advice, most hydrangeas do not require pruning. 

Be sure to grab a copy of the free Hydrangea Pruning Tips here.

---

Contents

• Types of Hydrangeas
  • Bigleaf – Hydrangea macrophylla
  • Panicle – Hydrangea paniculata
  • Smooth – Hydrangea arborescens
  • Climbing – Hydrangea petiolaris
  • Mountain – Hydrangea serrata
  • Oakleaf – Hydrangea quercifolia
• Growing Tips
• Frequently-Asked Questions
• How to Plant Hydrangea

Types of Hydrangeas

What kind of hydrangea do I have?

It’s very likely your hydrangea is one of the six types listed here.

1Bigleaf – Hydrangea macrophylla

Cityline® Venice Bigleaf Hydrangea macrophylla by Proven Winners

Bigleaf hydrangea (Hydrangea macrophylla):

• Also known as florist’s hydrangea, Hortensia, mophead, or lacecap
• Hardy to USDA zone 5
• Bloom on old wood
• Do not prune
• Protect in winter and during spring frosts to prevent buds damage

Bigleaf and Mountain hydrangeas are the only two types that can be forced to change color.

2Panicle – Hydrangea paniculata

Fire Light® Hardy Hydrangea paniculata by Proven Winners

Panicle hydrangea (Hydrangea paniculata):

• Hardy to zone 3
• Bloom on new wood when plant is at least two years old
• Prune in late winter or early spring
• May not bloom if sunlight is insufficient
• Limelight hydrangeas are also a favorite from this category.

3Smooth – Hydrangea arborescens

Incrediball® Smooth Hydrangea arborescens by Proven Winners

Smooth hydrangea (Hydrangea aborescens):

• A popular example is Annabelle hydrangeas.

• Hardy to USDA zone 3
• Bloom on new wood when plant is at least two years old
• Prune in later winter or early spring
• May not bloom if sunlight is insufficient

Wildlife Support

• Provides nectar and pollen to visiting insects.

4Climbing – Hydrangea petiolaris

Climbing hydrangea

Climbing hydrangea (Hydrangea petiolaris):

• Hardy to USDA zone 4
• Bloom on old wood
• Plants that are at least 5 years old bloom best
• Do not prune

5Mountain – Hydrangea serrata

Tiny Tuff Stuff® Mountain Hydrangea serrata by Proven Winners

Mountain hydrangea (Hydrangea serrata):

• Hardy to USDA zone 5
• Bloom on old wood
• Protect flower buds during spring frosts
• Do not prune

6Oakleaf – Hydrangea quercifolia

Gatsby Gal® Oakleaf Hydrangea quercifolia by Proven Winners

Oakleaf hydrangea (Hydrangea quercifolia):

• Hardy to USDA zone 5
• Bloom on old wood
• Plants that are at least 5 years old bloom best
• Do not prune
• Protect in winter

Growing Tips

Frequently-Asked Questions

How can I successfully grow hydrangeas?

• Choose a variety you love that is well-suited to your growing conditions and gardening zone.
• Hang on to your plant tag and read it! There is key information there for the successful growing.
• Choose the best location for sun, soil drainage, and protection from winter winds.
• Hydrangeas must have well-draining soil. They are fussy about their water: never let them dry out or sit in soggy soil. Even moisture all the way. Use this DIY test to check your drainage.
• Some morning and afternoon sun is ideal. Avoid scorching sun. Panicle hydrangeas including Fire Light are the one exception: they can tolerate full sun in northern climates.
• Most hydrangeas do not require pruning. Know which type you have and only prune if advised (see tips here for identifying and pruning your hydrangea).

Can I grow hydrangea from cuttings?

Yes, you can grow new plants from the ones you have by taking cuttings. The full instructions are here: How to Grow Hydrangea from Cuttings.

Can I change the flower colors?

• See Hydrangeas Blooms: How to Change From Pink to Blue (or Vice Versa) for complete instructions.

It is possible to intentionally change the flower color but only with certain varieties: bigleaf (Hydrangea macrophylla) and mountain (Hydrangea serrata). 

You may also find that your hydrangea shifts in color from pink to blue or blue to purple as it adapts to your garden soil.

The color is determined by the availability of aluminum in the soil which in turn can only be accessed within certain pH soil levels.

An established bigleaf or mountain hydrangea will be pink if the soil is alkaline and blue if the soil is acidic.

If a hydrangea has several color blooms like the one in the next photo, it may be transitioning to the current pH level or different parts of the garden soil may have different levels.

Color-Changing Myths Busted

• Burying pennies or rusty metal in the soil, or adding pine needles, coffee grounds, Epsom salt, vinegar, or aluminum foil near a hydrangea plant will not change the flower color.

Related: 10 Flower Growing Secrets & Common Mistakes

Help! My hydrangea is not blooming! What can I do?

Assuming the plant is healthy and at least two years old, here’s a few things that may be inhibiting blooms.

Is the hydrangea getting too much or too little sun, water, or fertilizer?

• Sun: It depends on the variety, but, generally, six hours of dappled sun per day is ideal. Too little or too much and they may not bloom.
• Water: You never want the plant to sit in dry soil but neither can they tolerate soggy feet. Is your plant in well-drained soil and evenly moist?

• Fertilizer: Most hydrangea benefit from fertilizing in the spring, but that’s it. Blooms are encouraged by phosphorus (P). Look for fertilizer like Holly-Tone (read about the benefits of organic fertilizers here) or a synthetic fertilizer with NPK 10-30-10 for blooms.
  Perhaps you used a fertilizer heavy with nitrogen that encouraged leafy growth instead of flowers? Or, too much was applied?
  
  Holly-tone by Espoma is an organic fertilizer suitable for hydrangeas in spring.

Has the plant been heavily pruned?

• A common mistake is to prune hydrangeas that do not need old growth removed and accidentally removing the wood that produces blooms.
  If this is the case, it will simply take time for things to regrow. Put away the pruners and your blooms will resume eventually.

How old is the hydrangea?

• Some hydrangea need to mature a few years before they will bloom reliably.

My hydrangea leaves are turning brown and falling off. What’s going on?

• Uneven watering—either too little or too much—can cause problems. Without enough water, leaf tips may turn brown and dry.
• Do the brown leaves have reddish-purple rings? This may be the fungus anthracnose. Try a google image search to check.
  If it is, carefully remove and dispose of the affected leaves and consult a garden nursery expert for treatment recommendations.

When should I transplant my hydrangea?

• The best time to move a hydrangea is late fall (before first frost) or early spring (before buds form).

If I can only have one, which type should I choose?

• My choice is the Limelight hydrangea by Proven Winners. You have to see it in person to grasp just how beautiful it really is. The more famous giant, mophead hydrangeas are well-known for their complete, over-the-top, massive mounds of flowers, and there is a definitely a place in the world for them. But the Limelight has the most graceful, under-stated elegance with its creamy-white flowers tinged with a hint of green that seems to work in just about any garden. Classic beauty! Love it.
• Limelight is one of the Hardy paniculata hydrangeas at Proven Winners which means it is suitable for colder climates as low as USDA zone 3.
• This pdf chart is useful for choosing hydrangea right for your zone at a glance: Proven Winners Hydrangea Comparison Table.

How Do I Plant Hydrangea?

This video shows how to properly plant a hydrangea:

I hope you have found this useful and enjoy a nice, long garden love affair with these gorgeous plants.

~Melissa the Empress of Dirt ♛