How to Identify What Type of Hydrangea You Have

Hydrangeas are a popular flowering shrub that come in a variety of types, each with their own unique characteristics. Learning how to identify the different types of hydrangeas can help you provide the proper care for your plants to keep them looking their best. Here are some tips on identifying hydrangea types based on their blooms, foliage, and other features.

Look at the Shape and Size of the Flower Blooms

One of the easiest ways to identify hydrangea types is by examining the shape and size of the blooms

• Bigleaf hydrangeas (Hydrangea macrophylla) have the largest blooms. They can be round, globe-shaped clusters called mopheads or flattened clusters called lacecaps.

• Panicle hydrangeas (Hydrangea paniculata) have conical-shaped blooms that start out lime green before turning white. As they age they can take on pink or red hues.

• Smooth hydrangeas (Hydrangea arborescens) have rounded, globe-shaped blooms similar to bigleaf mopheads but smaller in size. They are typically white but some cultivars have green or pink-tinged flowers

• Oakleaf hydrangeas (Hydrangea quercifolia) have cone-shaped blooms with tiny flowers clustered together. The blooms start white before aging to pink or brown.

• Climbing hydrangeas (Hydrangea anomala petiolaris) have flat-topped, lacy blooms.

Examine the Leaves Closely

The foliage is another distinguishing feature between hydrangea species.

• Bigleaf hydrangeas have large, oval-shaped leaves with a glossy finish. The leaves are 4-6 inches long with serrated edges.

• Panicle hydrangeas have oval leaves with serrated edges like bigleaf but slightly smaller in size.

• Smooth hydrangeas have heart-shaped, medium green leaves with a matte finish.

• Oakleaf hydrangeas, as the name implies, have leaves shaped like oak leaves with deep lobes. The foliage turns vibrant shades of red, orange, and purple in fall.

• Climbing hydrangeas have dark green foliage that is oval to heart-shaped.

Look at the Plant’s Growth Habit

Some species of hydrangea have very distinct growth habits that can aid in identification.

• Climbing hydrangeas are the only hydrangea that is a woody vine. It climbs by producing aerial rootlets along the stems.

• Smooth hydrangeas have an upright arching habit with willowy stems. They tend to be loose and open rather than compact.

• Oakleaf hydrangeas have a coarse, bulky shrub habit with thick, peeling stems.

• Panicle and bigleaf hydrangeas are both shrubs but panicles have a more conical shape compared to the rounded shape of bigleaf.

Notice Where the Plant Is Growing

Some hydrangea species are native to certain regions, which can provide clues to the type.

• Smooth hydrangeas are native to the eastern United States. They are commonly found growing in open woods and along streambanks.

• Oakleaf hydrangeas are also native to the southeastern U.S. They often grow on wooded slopes and in ravines.

• Panicle, bigleaf, and climbing hydrangeas originated from Asia. Panicles and bigleaf are common landscape shrubs while climbing hydrangea grows well on rocky slopes.

By carefully observing the flowers, foliage, habit, and growing location, you can accurately identify the most common types of hydrangeas. Proper identification will allow you to provide the best care and keep your hydrangeas thriving.

How to Tell Bigleaf vs. Smooth Hydrangeas Apart

Bigleaf (macrophylla) and smooth (arborescens) hydrangeas can look similar at first glance with their mophead style blooms. But there are a few key differences between these two common types.

Flowers:

• Bigleaf blooms can be 6-12 inches wide. Smooth hydrangea flowers are typically 3-6 inches wide.

• Bigleaf blooms are often pink or blue. Smooth hydrangeas are usually white.

Leaves:

• Bigleaf leaves are 4-6 inches long, oval shaped with serrated edges. Smooth hydrangea leaves are smaller (3-5 inches), heart-shaped, and with smoother edges.

• Bigleaf foliage is thick and glossy. Smooth leaves have a thinner, matte texture.

Stems:

• Bigleaf hydrangea stems are thick and sturdy. Smooth hydrangea stems are slender and arching.

Growth Habit:

• Bigleaf hydrangea shrubs tend to be dense and rounded or vase-shaped. Smooth hydrangeas are loose, open, and willowy.

Bloom Time:

• Bigleaf hydrangeas bloom in early summer on old wood. Smooth hydrangeas bloom in summer on new wood into fall.

Distinguishing Features of Oakleaf Hydrangeas

With their large, lobed foliage and cone-shaped blooms, oakleaf hydrangeas have some very distinctive features that make them easy to identify. Here are a few key things to look for:

• Leaves – As the name suggests, oakleaf hydrangea leaves resemble those of oak trees. They have deep lobes and can grow up to 8 inches long. The foliage turns stunning shades of red, purple, and orange in autumn.

• Flowers – Oakleaf hydrangea blooms are cone-shaped panicles up to 12 inches long that start out white before fading to pink or brown. The tiny individual flowers cluster together to form the cones.

• Bark – One of the most distinctive features of oakleaf hydrangeas is their bark. It peels and flakes off in large strips, giving mature trunks a textured, exfoliating appearance.

• Habit – Oakleaf hydrangeas have a coarse, bulky habit with thick, sturdy stems. They tend to grow wider than tall and have an informal look.

• Size – At maturity, oakleaf hydrangeas typically grow 4-6 feet tall and up to 8 feet wide. Some compact varieties reach just 3-4 feet tall and wide.

• Hardiness – Oakleaf hydrangea is cold hardy to zone 5 and thrives in areas with hot, humid summers.

• Native Range – This species is native to the southeastern United States from North Carolina to Florida and west to Louisiana. It’s commonly found growing on rocky slopes, ravines, and woodland edges.

So if you come across a hydrangea shrub with huge, lobed leaves, peeling bark, massive cone-shaped blooms and excellent fall color – chances are good it’s an oakleaf hydrangea!

Identifying Panicle Hydrangeas

With their large, cone-shaped blooms, panicle hydrangeas have a very distinct appearance. Here are some tips for identifying these popular landscape shrubs:

• Flower shape – Panicle hydrangea flowers are cone or pyramid-shaped, 6-12 inches long and 4-8 inches wide. They are composed of tiny, clustered florets.

• Flower color – The blooms start out lime green before turning white. As they age, they can take on pink or red hues depending on variety.

• Leaves – The leaves are oval shaped with serrated edges. They are typically 4-6 inches long.

• Bark – The bark is tan-gray to brownish on older branches. On young branches, the bark is smooth and gray.

• Growth habit – Panicle hydrangeas have an upright, conical growth habit with sturdy stems. Their form is more treelike than the rounded shape of bigleaf hydrangeas.

• Size – They range in size from 3-4 feet for dwarf varieties up to 6-8 feet tall for standard cultivars. Width is typically equal to or up to 2 feet less than the height.

• Hardiness – These are cold hardy from zone 4-8 and can tolerate hot, humid summers. They bloom on new wood so winter dieback doesn’t affect flowering.

• Native range – Panicle hydrangeas are native to China and Japan. They thrive in temperate regions.

• Bloom time – Flowers appear in mid to late summer on the current season’s growth. They continue blooming into fall in some areas.

If you come across a hardy, conical shrub with huge cone-shaped blooms, it’s likely a panicle hydrangea. Proper identification will help you care for these beautiful landscape plants.

Climbing Hydrangea Key Features

Here are the key things to look for when identifying climbing hydrangea vines:

• Growth habit – Climbing hydrangea is the only hydrangea species that grows as a vine. It climbs by producing aerial rootlets along the stems.

• Flowers – The blooms are flat-topped, lacy clusters 3-6 inches wide that resemble those of a lacecap hydrangea. They are typically white turning pinkish with age.

• Leaves – The leaves are dark green, oval to heart-shaped with a glossy finish. They grow 3-5 inches long.

• Size – At maturity, climbing hydrangea vines can reach lengths of 20-80 feet. Spread can reach 6 feet or more.

• Bark – The bark is tan-gray and peeling on mature stems. Younger stems have grayish bark that becomes increasingly textured as it ages.

• Native range – Climbing hydrangea is native to Japan, Korea, and Siberia. In the landscape, it thrives in zones 4-8.

• Habitat – This vine grows well on rocky slopes, cliffs, and open woodlands. It also thrives when planted on porches, fences, and structures.

• Flowers – Climbing hydrangea blooms in early summer on the previous year’s growth. Flower color ranges from greenish-white to pink as they age.

So if you come across a flowering vine that climbs by attaching itself, produces flat-topped lacecap blooms, and has heart-shaped foliage, it’s likely a climbing hydrangea. Identifying these key features will help you properly care for this beautiful plant.

Tips for Identifying Your Hydrangeas

Here are some quick tips for identifying common hydrangea species:

• Look at the shape and size of the blooms – rounded mopheads, conical panicles, or lacy lacecaps.

• Examine the foliage – bigleaf, oakleaf, heart-shaped, or climbing.

• Note the shrub habit – rounded, conical, arching, vine-like.

• Consider the native range – smooth and oakleaf hydrangeas are native to the Southeast.

• Look at where it’s growing – on slopes, in the woods, along streambanks.

• Check the bark – it peels on oakleafs and climbing types.

• Notice when it blooms – bigleaf and oakleaf on old wood vs. smooth and panicle on new.

• See if it climbs – only the climbing hydrangea vines by attaching to surfaces.

By carefully observing the flowers, leaves, growth habit, and other characteristics, you can identify the hydrangea species growing in your garden. This will allow you to provide proper care for healthy, vigorous plants.

To determine if your hydrangea blooms on old or new wood, observe when it flowers and how the stems look during the growing season. If it flowers in spring or early summer and the buds are visible on the stems from the previous year, it blooms on old wood.