How to Identify Your Hydrangea

There are many different types of hydrangea, although the word usually brings one to mind in particular. But you might not know which type that is! So, to help you figure out which hydrangea you have (or which you’d like to have), we’ve listed the most common hydrangea types below. Each section has photos and notes to help you confirm the ID. The three main ways to identify a hydrangea are by flowers, leaf, and overall habit. Use the example photos below to compare to your plant in particular. 

Here are a few hydrangea related terms to know before you get started:

  • Leaf margin – the leaf’s edge
    • Serrated – a jagged line
    • Entire – a smooth line
  • Fertile florets – a tiny ball at the center of the flower, sometimes open and fuzzy
  • Infertile florets (also known as sterile florets) – a part of the flower that looks a lot like a petal, but technically isn’t
  • Lacecap flower – a bloom filled with fertile florets, accented by infertile florets around the outside
  • Mophead flower – a bloom comprised mostly of sterile florets, with fewer fertile florets that are hidden below the sterile ones

Two of the common names for Hydrangea macrophylla come from its appearance – mophead and bigleaf. Its other common names are French hydrangea, florist’s hydrangea, and hortensia. 

Care – Pruning is not recommended. These plants flower on old wood and some, like the Let’s Dance series, rebloom. Any pruning will remove flowers. They naturally keep a rounded habit, so you won’t typically need to do any shaping. You can deadhead in autumn or early spring if you’d like. Cover in winter and very early spring if you experience harsh temperature drops, which will protect the tender buds during cold snaps.

Flowers

Its blooms are typically dense and rounded. However, there are a few (very few) out there that have lacecap flowers.

Foliage

Its leaves are wide, thick, and vaguely heart-shaped. The leaf edge (also called the leaf margin) is serrated, giving it a jagged or toothed look.

Form

Its overall appearance is very rounded. At the beginning of its bloom time, flowers are displayed right on top of the foliage. As new growth is produced, the flowers get slightly tucked in.

Mountain hydrangeas are very similar to bigleaf hydrangeas, but they differ in two major ways. Mountain hydrangeas are more cold hardy,  and at present are only available with lacecap flowers.

Care – No need to prune. These plants reliably flower on old wood and the Tuff Stuff series reblooms. Pruning or cutting back removes flower buds, but you can deadhead when you’d like. Thanks to the reliable cold hardiness and sheer number of old wood buds, you don’t have to cover it during the winter.

Flowers

For now, all mountain hydrangeas have lacecap flowers.

Foliage

Very similar to the foliage of a bigleaf hydrangea. It gets better fall color, often adapting rich purples and reds.

Form

Has a horizontally layered look. This is highlighted when the plant is flowering.

Very unique looking! Although it shares a similar flower shape with a panicle hydrangea, the foliage’s resemblance to its namesake foliage will help you clearly identify an oakleaf hydrangea. 

Care – Flowers develop on old wood, so pruning isn’t recommended. It grows pretty slowly and naturally has a whimsical habit that looks best when untouched. Very cold hardy (USDA zones 5-9), so oakleaf hydrangeas do not need winter protection.

Flowers

Long, football-shaped blooms are generally filled with fertile florets covered with infertile florets. The density of the petal-like structures varies, sometimes looking like lacecaps and others looking very dense.

Foliage

Very large oakleaf-shaped foliage is the hallmark of this plant. Stems and leaves are lightly fuzzy.

Form

Mature plants with foliage have a generally rounded shape. When leaves have dropped, you can see a very twisty set of stems supporting. Young plants have long irregular stems and very little branching.

A favorite for the fall garden! Panicle hydrangeas typically have an incredible fall color show as the flowers shift from white to varying shades of pink and red. Another common name for Hydrangea paniculata is PeeGee hydrangea; some people also call them hardy hydrangeas because they are very cold tolerant (USDA zones 3-8).

Care – Panicle hydrangeas bloom on new wood. While you can leave them unpruned (they will do just fine), we feel panicles look best with a yearly prune. It gives them shape and bloom display, as well as thicker, sturdier stems.

Flowers

Long, conical blooms are shaped like footballs. Most of the time, these blooms are dense. They may be mophead or lacecap.

Foliage

Honestly, these look like a typical leaf. Technically speaking, they have an ovate shape and the edges are serrated. 

Form

These upright habits are densely branched and packed with foliage. Younger plants have foliage that reaches the ground. Older plants can sometimes have a gap between the foliage and the ground, exposing their thicker branches.

Reblooming hydrangea - Hydrangea macrophylla x serrata

This is a hybrid between mountain and bigleaf hydrangeas, combining the best qualities of both. It’s cold-tolerant and comes with different flower forms.

Care – These hybrids reliably bloom and rebloom. They respond well to some shaping (but it isn’t necessary), even though it will remove some blooms. Deadhead when you’d like! There is no need to cover due to the increased cold hardiness.

Flowers

Flowers on a hydrangea hybrid can be rounded like a bigleaf hydrangea or lacecap like a mountain hydrangea.

Foliage

Leaves are slightly heart-shaped with a serrated edge.

Form

Young plants are rounded. When new growth pops up, it gives the habit a fun, irregular look. If the plant is regularly left undeadheaded, it will develop a multi-level look.

A longtime favorite. Smooth hydrangeas have a few common names, including Annabelle hydrangea and wild hydrangeas. They are beloved for their uniform look, producing blooms evenly on their rounded forms. 

Care – Smooth hydrangeas bloom on new wood. While they don’t technically need pruning, they do really benefit from a yearly trim. It helps give them an orderly rounded habit and ensures thick, vigorous growth for sturdy stems and lots of flowers. 

Flowers

Dense, rounded flowers are the typical view for a smooth hydrangea. There are a handful of exceptions with lacecap flowers, like Invincibelle Lace® smooth hydrangea.

Foliage

Very flat leaves with a prominent tip, often with a matte sheen. Leaf margins have a regular serration.

Form

A super upright habit filled with straight branches. Even if the plant is pruned, it generally keeps a rounded habit.

Less Common Hydrangeas

A totally new type of hydrangea! It was introduced to fill a unique role for gardeners. With its long stems, it can be used in hanging baskets, as ground cover, or as a cascading feature over low walls.

Care – Cascade hydrangeas form their flowers on old wood all along the branch. Given the total coverage of buds, they shouldn’t be pruned. Deadheading would be tedious and unnecessary and could potentially remove the flowers. 

Flowers

The original Cascade Hydrangea® is a lacecap, but new varieties exhibit mophead flowers.

Foliage

Foliage is narrow, usually shiny and thick, and has a  serrated edge.

Form

On younger plants, the habit is springy and grows upward and outward. Older plants drape as the stems get longer and heavier.

It can be confusing to differentiate between climbing hydrangeas (Hydrangea petiolaris) and Japanese hydrangea vines (formerly known as Schizophragma hydrangeoides, but recently – and thankfully! – reclassified to Hydrangea hydrangeoides), but it’s safe to say, if you see a hydrangea-like planting climbing upward, you’ve got a hydrangea vine. The only substantial difference between the two is that sterile florets on a climbing hydrangea are made up for four petals, creating a traditional flower shape, whereas the Japanese hydrangea vine, below, sports a single sail-like petal.

Care – Japanese hydrangea vines bloom on old wood and grow to be gigantic, so it is not recommended to prune them and nearly impossible to deadhead them. They naturally make their way up a vertical surface. All you need to do is get them started in the right direction when they’re young, wait a while, and enjoy the view.

Flowers

Always lacecaps!

Foliage

Very flat foliage with a sharp serrated edge. Leaves are usually pretty thick and sturdy. 

Form

Mature plants often engulf the base of a structure (often trees) and dwindle in density as they grow upward. Young plants are heavily foliated near the ground, with a few stems reaching upward.

Still having trouble identifying your hydrangea type? Reach out to us with photos and any information you have on them. We can help! If you’re wondering whether or not your hydrangea should be pruned, we recommend putting the pruning shears down until you have a correct identification and are sure about what your specific plants need.

Written by
Kristina Howley

Kristina Howley

I am all in when it comes to gardening. Almost every part of the experience delights me – new leaves emerging in spring, pollinators buzzing in summer, birds devouring berries in fall, and the somber beauty of seed heads in winter. Thanks to a background in horticulture and gardening my own clay-filled, flowery USDA zone 5b plot, I’ve learned plenty of practical things as well. I like sharing these joys and lessons with my fellow gardeners and soon-to-be gardeners any way I can.

Share:

Get The Latest Updates

Love plants? So do we!

Subscribe to our bi-weekly newsletter for inspiration, information, and ideas to make your garden or landscape more beautiful and easier to care for.

Related Posts

Close Wishlist
Categories

Scholarship Application

*Completing this form does not guarantee a scholarship. A staff member will confirm scholarship availability directly. Receipts must be submitted within 10 weeks from the conclusion of the event.
Gardening Simplified magazine
[everest_form id="4997"]