How Big Will Hydrangeas Grow When Fully Mature?

Curious to know how big your hydrangeas will grow when fully mature? While this will depend on many factors, including the type of hydrangea you grow, there are some basic characteristics of this popular shrub. In this article, gardening expert and hydrangea enthusiast Jill Drago examines the typical hydrangea size by species, with a comprehensive growth chart for each.

Big flowering hydrangeas growing in garden with green foliage.

Often, when you think of a hydrangea, your favorite species will come to mind, which is different for each of us. Did you know that each of the most popular species of hydrangeas grows to different heights?

Hydrangeas have many uses in the garden, from container plantings to privacy screens and hedges. The size of your space as well as the mature size of the variety you choose is very important to the overall health and success of your plantings.

So, how big do hydrangeas get? Which one should you choose for your yard? Let’s dig in and find out.

Contents

The Short Answer

There are six species within the hydrangea genus that are popular amongst today’s gardeners. Each one of these species has a different size. The smallest comes in at 3 feet, and the largest, the climbing hydrangea, can grow to 40 feet.

The Long Answer

Many factors contribute to the size of your hydrangeas at maturity. The variety of hydrangeas you have will be the best way to determine their size. Sizes can vary greatly not only between species but also within species. There are many compact varieties that will come in at the lower end of the height chart.

Other elements will factor into the size of your hydrangeas. Ensuring they receive the proper sunlight, are getting enough water, grow in the right climate, are planted in favorable soil conditions, and are pruned can be considerations for how big they grow. Let’s take a look at each factor you’ll need to consider when growing hydrangeas.

Sunlight

Partial sun is ideal for planting hydrangeas so they can reach an optimal size for your garden. If you have a sunny spot in your garden, choose a panicle variety as they will do best there. Most hydrangeas prefer morning sun and afternoon shade.

Water

A good slow, deep watering about three times each week should be enough to keep hydrangeas growing in a healthy way. Water in the morning before the sun gets too high. In hotter climates, more water may be necessary. Never water from above, as this can promote fungal diseases.

Soil

Hydrangeas thrive in acidic soil that is well-draining. The soil should never be soggy. Compost, peat moss, dried leaves, or other organic materials can amend soil to make it drain better.

Climate and Temperature

Hydrangeas are hardy perennials that grow best in USDA hardiness zones 3-7. These mild climates are ideal for health and vitality, allowing them to grow to their full potential.

Pruning

Cutting back the branches can help them to grow back larger, fuller, and with more blooms. Just be sure you know the species you have in your garden as this affects when you should prune them for best results.

Sizing Chart by Species

As mentioned above, the species of hydrangea you have in your garden is the best-determining factor of how big it will get. Here is a chart with each of the six hydrangea species and their general size for quick reference.

Scientific Name Common Name Height Width
Hydrangea anomala Climbing hydrangea 30-40 feet 5-6 feet
Hydrangea arborescens Smooth hydrangea 3-5 feet 3-5 feet
Hydrangea macrophylla Bigleaf hydrangea 3-6 feet 3-6 feet
Hydrangea paniculata Panicle hydrangea 5-15 feet 6-12 feet
Hydrangea quercifolia Oakleaf hydrangea 6-8 feet 6-8 feet
Hydrangea serrata Mountain hydrangea 2-4 feet 2-4 feet

Hydrangea anomala

Vining hydrangea plant with oval-shaped leaves that come to a point and have serrated edges. The white lacecap flowers bloom all over the plant. Some of the blooms are young and still a light green color.
Climbing or vining hydrangeas can grow to 40 feet when planted near a trellis or wall.

The climbing hydrangea is a stunning variety of hydrangea that works just as well climbing up an arbor or as a creeping ground cover under a large tree. This vine will produce large white lacecap flowers in the summertime.

Try training a climbing hydrangea up a trellis, a tree trunk, or along a fence. This species will do best climbing up something that is textured as opposed to smooth, like a vinyl trellis. This vine can reach heights of 40 and even 50 feet!

Hydrangea petiolaris

Close-up of a large flowering bush Hydrangea anomala ssp. Petiolaris in the garden. It is a climbing hydrangea with large, heart-shaped, glossy dark green leaves. Its flowers are profuse and frothy, appearing in clusters of white inflorescences. The flowers of this plant can reach impressive sizes, reaching up to 8 inches in diameter.
Hydrangea petiolaris is a popular climbing variety known for its abundant white flowers.
botanical-name botanical name Hydrangea anomala ssp. Petiolaris
sun-requirements sun requirements Partial Shade to Shade
height height 30-40 feet tall, 5-6 feet wide
hardiness-zones hardiness zones 4-9

This is the classic climbing hydrangea that has caused all of the other varieties to gain popularity. The white flowers on this climbing vine are foamy and abundant. These flowers can reach up to 8 inches in diameter. In the winter, the bark of this vine is red and slightly peeling, adding beauty to an otherwise barren garden.

Hydrangea arborescens

Close-up of a blooming smooth hydrangea in a garden. The lush shrub has large heart-shaped dark green leaves and massive rounded creamy white inflorescences.
This popular species has massive round flower heads and can reach heights of up to 5 feet.

The smooth hydrangea is native to North America, making it one of the easiest to grow. Their large flowers have been known to weigh down the branches a bit in some varieties, such as ‘Annabelle.’

However, there have been many improvements made with new varieties that claim to defeat the drooping. The flowers of the smooth hydrangea are white or green and will last throughout the summer.

In general, smooth hydrangeas will grow a bit wider than they do tall. This characteristic makes it a good choice for a low-growing border or a mass planting along a woodland edge. This species also grows very nicely in large containers.

Hydrangea ‘Incrediball’

Close-up of a blooming Hydrangea arborescens 'Incrediball' in a garden. Hydrangea is a lush shrub with large heart-shaped dark green leaves and massive rounded creamy white inflorescences.
‘Incrediball’ is an enhanced smooth hydrangea variety with strong stems that bear massive creamy white flowers.
botanical-name botanical name Hydrangea arborescens ‘Incrediball’
sun-requirements sun requirements Full sun to Partial sun
height height 4-5 feet tall and 4-5 feet wide
hardiness-zones hardiness zones 3-8

Incrediball’ is an improved species of smooth hydrangea. The stems are sturdy enough to support the weight of the massive flowers, which can reach up to 12 inches across. These flowers open in a fresh shade of green and mature to a creamy white as the season progresses.

Hydrangea macrophylla

Shrub with dark green oval shaped foliage covered in round clusters of blue flowers. Other plants, one with pink flowers to the left, grow in the background.
These beautiful blooming shrubs can reach up to 6 feet tall.

This species is most known for its blue blossoms. While the blue flowers on the bigleaf, or French hydrangea, are stunning, there are also species with pink, purple, or white flowers.

While all hydrangeas thrive in acidic soil, the acidity of the soil is what will control the color of your flowers. The more acidic your soil, the bluer or purple your blossoms will be. The sweeter or more alkaline your soil is, the pinker the flowers will be. This holds true unless you have a species with white blooms; these flowers will remain white no matter the soil pH.

The size of the bigleaf hydrangeas makes the shrub very versatile. Growing to about 6 feet tall, you can easily use this species as a foundation planting, a small hedge, or throughout a partially shaded garden bed.

Hydrangea ‘Pia’

Top view, close-up of a blooming compact bush of hydrangea macrophylla 'Pia'. Hydrangea has large rounded inflorescences of many small four-petal pink flowers. The leaves are bright green, heart-shaped with serrated edges.
Hydrangea macrophylla ‘Pia’ is a compact cultivar with pretty pink flowers that can fit well in small spaces.
botanical-name botanical name Hydrangea macrophylla ‘Pia’
sun-requirements sun requirements Partial Sun
height height 2-3 feet tall and 2-3 feet wide
hardiness-zones hardiness zones 5-9

‘Pia’ is a very pretty pink flowered bigleaf hydrangea. On the smaller side, ‘Pia’ can be tucked into many spaces in your garden and is especially beautiful in containers.

The 4-inch blossoms on this cultivar will remain pink despite the pH of your soil, but you may notice variations of the exact shade of pink.

Hydrangea paniculata

Close up of several cone-shaped flower clusters growing on a shrub with dark green oval-shaped foliage. Most of the flower clusters are pure white, but some of them have faded pink flowers at the base of the panicle.
Reaching heights of up to 15 feet, panicles are one of the largest growing species.

The largest shrub of the species is also the sun-loving species. These large hydrangeas form large cone flowers that tend to be multi-colored depending on the time of the season. Most of these blossoms will open white and mature to shades of green, pink, or red.

Hydrangea paniculata has varieties that will reach up to 15 feet, while most of them max out around 8 feet tall. Panicles are great when used for hedges or privacy screens. Just keep in mind that these shrubs are not evergreen and they will not have leaves over the winter. 

Hydrangea ‘Fire Light’

Large flowering bush Hydrangea paniculata 'Fire Light' in a sunny garden. The bush has upright stems covered with oval dark green leaves. Conical inflorescences of crimson flowers grow on the tops of the stems.
Hydrangea paniculata ‘Fire Light’ is a stunning variety with large flowers that mature into a vibrant raspberry color.
botanical-name botanical name Hydrangea paniculata ‘Fire Light’
sun-requirements sun requirements Full sun to Partial sun
height height 6-8 feet tall and 6-8 feet wide
hardiness-zones hardiness zones 3-8

Another gorgeous cultivar, ‘Fire Light,’ is loaded with large flowers that will begin their journey as a creamy white and age to light pink, finally resting in a vibrant shade of raspberry. The strong stems will support these bright flowers all season long.

Hydrangea quercifolia

Close up of three cone-shaped flower clusters with pure white flowers growing among green lobed leaves that look like oak leaves. Many of the leaves have red speckles on the edge that feed into the center of the leaf.
These unique shrubs can reach heights of up to 8 feet tall.

Hydrangea quercifolia, also known as the oakleaf hydrangea, has the most interesting foliage of all the species. Their leaves have a similar shape to that of the leaves of an oak tree.

They often take on a lovely red color in the fall, adding to their beauty. The flowers are long and conical and are often in shades of white, pink, or red.

This species can reach heights of up to 8 feet. They are lovely when used on a woodland edge.

Hydrangea ‘Pee Wee’

Close-up of a flowering hydrangea quercifolia ‘Pee Wee’ bush in the garden. It is a small plant growing to about 5 feet tall and wide. It has vertical cone-shaped white flowers. The leaves are bright green in color, lobed with serrated edges, and resemble oak leaves in shape.
‘Pee Wee’ oakleaf hydrangea is a compact variety with cone-shaped white flowers that turn pink.
botanical-name botanical name Hydrangea quercifolia ‘ Pee Wee’
sun-requirements sun requirements Full sun to Partial sun
height height 4-5 feet tall and 4-5 feet wide
hardiness-zones hardiness zones 5-9

‘Pee Wee’ is the perfect oakleaf hydrangea for smaller gardens, coming in at just about 5 feet tall and wide. The upright cone-shaped flowers bloom as white and mature into a rosy shade of pink, while the leaves are a fresh green until autumn when they take on a hue of wine. ‘Pee wee’ blooms in the early summer and will last into the fall.

Hydrangea serrata

Close up of a lacecap flower cluster growing among lush green foliage. The leaves are oval-shaped and slightly serrated. The flower cluster has tiny blue sphere-shaped flowers in the center and four petaled pure white flowers growing in a circle around the central blue flowers. The center of each white flower has a tiny blue dot.
Mountain hydrangeas are on the smaller side and grow up to about 4 feet tall.

This species of hydrangea is a subspecies of Hydrangea macrophylla. The main differences are that the mountain hydrangea, Hydrangea serrata, is a little bit smaller than the bigleaf, and the flowers they produce are of the lacecap variety.

It is not quite clear if these flowers are sensitive to the pH of your soil as the bigleaf species is, but you may have some success playing around with your soil if you want.

This species will grow to about 4 feet tall. This petite size makes them a great addition to your perennial gardens or in the middle of a foundation garden.

Hydrangea ‘Bluebird’

Close-up of Hydrangea serrata 'Bluebird' in bloom. Hydrangea has beautiful inflorescences resembling flat lace caps. Inside the inflorescence there are many tiny purple flowers, surrounded by outer single four-petalled sterile flowers that are pale blue-purple.
Hydrangea serrata ‘Bluebird’ features abundant blue lacecap flowers that bloom from summer to fall.
botanical-name botanical name Hydrangea serrata ‘Bluebird’
sun-requirements sun requirements Full sun to partial sun
height height 3-4 feet tall and 3-4 feet wide
hardiness-zones hardiness zones 6-9

As the name implies, this mountain hydrangea is covered with pretty blue lacecap flowers from summer all the way into the fall. The leaves of this variety will turn a bright red when autumn arrives.

Final Thoughts

Keeping the full size of your hydrangea in mind is so important when you are planting these flowering shrubs in your garden. Allowing the shrubs ample space will give your hydrangea the best shot at thriving.

This is also the best way to get your hydrangeas to grow quickly. With six different species that grow in six different sizes, you will surely find a hydrangea that fits any space in your garden.

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