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How do you prune a hydrangea bush


Pruning Hydrangeas - FineGardening

I know people are confused about how to prune hydrangeas because I get asked about it all the time. The three most common reasons for their confusion are the plant’s dead-looking appearance in winter, its failure to bloom in summer, and the reasoning that because it’s a shrub it needs to be pruned. But these popular woody plants can live long, floriferous lives without ever feeling the cold blade of a pair of Felcos. Hydrangeas, though, can handle pruning (which, if done at the wrong time, may be the cause for the lack of flowers), and sometimes you might want or need to cut them back a bit. For example, you may not like the look of the fading blooms, or your shrub may be a bit too tall. Pruning hydrangeas can also improve a shrub’s vigor and increase the size of its flowers.

Not all of these shrubs should be pruned at the same time. Those that bloom on old growth should only be pruned after flowering. Others bloom on new growth and should be pruned before they wake up in spring or as they are going dormant in fall.

Hydrangeas that bloom on old wood

Bigleaf hydrangea. Photo: Steve Aitken

Bigleaf hydrangea. Photo: courtesy of hydrangeasplus.com

Oakleaf hydrangea. Photo: Melissa Lucas
  1. Bigleaf hydrangeas (Hydrangea macrophylla cvs., USDA Hardiness Zones 6–9)
  2. Bigleaf hydrangeas (H. serrata cvs., Zones 6–9)
  3. Oakleaf hydrangeas (H. quercifolia cvs., Zones 5–9)

Prune after the flowers start to fade in late summer

To determine if your hydrangea blooms on old wood, think about when it flowers. Shrubs with this characteristic generally begin blooming in early summer and peter out by midsummer, though sporadic blooms may appear afterward. These shrubs form next year’s flower buds in late summer or early fall as the days get shorter and temperatures cool off. To reduce the risk of removing these buds, prune just as the flowers begin to fade. Often, the earlier you get it done after bloom, the quicker the shrub can recover, producing more and larger blooms next season.

1. To tidy up, remove old blooms

Gardeners who want to maintain a tidy appearance can snip off spent blooms just below the flower head and remove any wayward or straggly canes at the soil line.

2. To improve vigor, remove the oldest canes

When a hydrangea gets old and woody, it can produce smaller blooms. Regular removal of a few of the oldest canes at the soil line can keep the shrub vigorous, producing large and abundant flowers. The same method can keep a shrub from getting too tall by targeting the tallest canes for removal.

 

Watch a video on pruning bigleaf hydrangeas

Almost everybody is enchanted by the large, mophead blooms of bigleaf hydrangea (Hydrangea macrophylla and cvs. , Zones 4–9). And it seems that almost everybody who grows these flowering shrubs has questions about pruning them. The thought is often that, because they are shrubs, they must need to be pruned. Some gardeners also think that cutting back their hydrangea might make it bloom. Neither of these thoughts is correct. Bigleaf hydrangeas grow just fine without any pruning, and making your cuts at the wrong time can actually remove the flower buds you are hoping to get.

Bigleaf hydrangeas typically bloom on old wood, meaning the flower buds are on the growth produced the previous season. If you prune them before they flower, you will be removing the flower buds. Many newer varieties actually produce buds on old and new wood, so pruning too early doesn’t stop the whole show, just a good portion of it. But if your hydrangea isn’t blooming, poorly timed pruning is often the culprit. The best time to cut back a bigleaf hydrangea is just after it is done blooming. The shrub then has ample time to set new growth and harden off before winter.

If you do decide you need to prune your bigleaf hydrangea, this video will give you the information you need to time your cuts correctly and identify where to make them on the shrub. The only tools you will need are hand pruners and perhaps a pair of loppers to reach down into the hydrangea. Also, be sure to wear some safety glasses. You might not think they are cool, but it is very easy to poke your eye on a stem as you are trying to see down into the shrub. And a poke in the eye is never cool.

So stay safe, time it right, and enjoy your shrub.

Hydrangeas that bloom on new wood

Panicle hydrangea. Photo: courtesy of provenwinners.com

Smooth hydrangea. Photo: Michelle Gervais
  1. Panicle hydrangeas (H. paniculata and cvs., Zones 4–8)
  2. Smooth hydrangeas (H. arborescens and cvs., Zones 4–9)

Cut back these shrubs in late winter before new growth begins

Because they need to grow and set buds the same year that they bloom, shrubs that flower on new wood generally start blossoming later than old-growth bloomers, beginning in midsummer and continuing until the first frost. These shrubs are forgiving if pruning is not done at a certain time as long as you avoid pruning when the flower buds are opening.

1. To get bigger flowers, cut them all the way back

In late winter or early spring, these shrubs can be cut all the way back to the ground. Smooth hydrangeas will produce much larger blooms if pruned hard like this each year, but many gardeners opt for smaller blooms on sturdier stems.

2. To reduce flopping, leave a framework of old growth

Some hydrangeas’ branches often fall over under the weight of their blooms, especially after overhead irrigation or after a good rain. One way to alleviate this flopping is to cut the stems to a height of 18 to 24 inches to provide a sturdy framework to support new growth.

 

—Janet Carson is the horticulture specialist for the University of Arkansas Cooperative Extension Service.

Photos, except where noted: Steve Aitken

Illustrations: Chuck Lockhart

How to Prune Hydrangeas

Match the Pruning Method to the Species

By

Marie Iannotti

Marie Iannotti

Marie Iannotti is a life-long gardener and a veteran Master Gardener with nearly three decades of experience. She's also an author of three gardening books, a plant photographer, public speaker, and a former Cornell Cooperative Extension Horticulture Educator. Marie's garden writing has been featured in newspapers and magazines nationwide and she has been interviewed for Martha Stewart Radio, National Public Radio, and numerous articles.

Learn more about The Spruce's Editorial Process

Updated on 09/11/22

Reviewed by

Julie Thompson-Adolf

Reviewed by Julie Thompson-Adolf

Julie Thompson-Adolf is a Master Gardener and author. She has 30+ years of experience with year-round organic gardening; seed starting and saving; growing heirloom plants, perennials, and annuals; and sustainable and urban farming.

Learn more about The Spruce's Review Board

The Spruce

Project Overview

Hydrangeas make beautiful focal points in the garden, and they require minimal care other than pruning and fertilizing. Although many hydrangeas have interesting foliage and bark, most are grown for their large, showy blossoms. If hydrangeas don’t bloom for a season, it's usually due to one of three reasons: They didn't get enough sun, an early frost or cold spell killed the buds, or they were pruned at the wrong time. Learning how to prune your hydrangeas, whether is should be done in the summer or other months, can make the difference between a lush crop or lackluster output of blooms the next year.

In general, to prune hydrangeas in summer, you'll need to remove dead or crossing stems, cutting them close to the ground. To rejuvenate the hydrangea, remove up to one third of the older living stems down to the ground each summer. Keep in mind that buds for blooms are produced on old wood; thus, the more old wood you eliminate, the less beautiful the floral display will be during spring and summer.

How and when you prune hydrangeas varies according to the six different species of hydrangea commonly grown as garden plants. Thus, you'll need to know (or determine) what species you have in order to prune at the right time of year.

Tip

Can you deadhead hydrangeas in the summer? Yes, because deadheading spent flower heads will not harm the plant. Deadheading and pruning (removing more than just the flower head) hydrangeas are two different techniques.

When to Prune Hydrangeas

Like most woody flowering shrubs, when you prune a hydrangea depends on whether it blooms on new wood (growth produced in the current season) or old wood (growth from the previous season). In the case of hydrangeas, this is complicated by the fact that some species of hydrangea bloom on old wood, while others bloom on new wood.

Shrubs that bloom on new growth should be pruned in the late winter or early spring just before the critical new growth has started. This will maximize the amount of new growth and the number of flowers your shrub produces. Shrubs that bloom on old growth, on the other hand, should be pruned immediately after their flowers have faded. This gives the plant plenty of time to develop wood that will be "old" by the time the next season's flower buds emerge.

If you don't immediately know the type of hydrangea you own, it's relatively easy to determine it based on simple observation of its leaves and flowering pattern.

When to Prune Different Types of Hydrangeas
Category Blooms on old or new wood When to prune
Bigleaf hydrangea Old Immediately after flowers fade
Smooth (wild) hydrangea New Late winter or early spring before new growth starts
Panicle (peegee) hydrangea New Light pruning in late winter or early spring
Oakleaf hydrangea Old Summer after the flowers fade
Mountain hydrangea Old Immediately after flowering
Climbing hydrangea Old Winter or early spring, only when necessary to control size

14 Beautiful Types of Hydrangea to Grow

Before Getting Started

In general, flowering woody shrubs that bloom on new wood tolerate, or even thrive on, fairly aggressive pruning, while those that bloom on old wood require more careful restrained pruning. This is especially true of hydrangeas. The two species that bloom on new wood—panicle (peegee) hydrangeas and smooth (wild) hydrangeas—do well with an aggressive annual pruning that removes as much as one-third to one-half of the total mass of the shrub. The four species that flower on old wood—bigleaf, oakleaf, mountain, and climbing hydrangeas—may not need pruning at all, except when you are pruning to keep their size or shape in check.

Watch Now: How to Prune Hydrangeas

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How to Prune Bigleaf Hydrangea (H. macrophylla)

Bigleaf hydrangeas are one of the species that bloom on old wood, meaning they set their flower buds from late summer to early fall. Thus, if you mistakenly prune in the spring or even late fall, it will remove the flower buds and any chance of getting blooms for a year. Bigleaf hydrangeas actually do fairly well without any pruning at all, but if necessary to control its shape or size, do the pruning carefully just after the flowers have faded, never removing more than one-third of their total growth.

The Spruce / Almar Creative

  1. Deadhead Spent Flowers

    Spent flowers can be trimmed away as they fade to keep the plant looking tidy. Simply clip away the blooms using bypass pruners.

  2. Prune Away Dead and Weak Stems

    When most of the flowers have faded, it's time for pruning. Begin by pruning away stems that are clearly dead or weak. But don’t prune all the old wood because this is what will keep flowering as the new growth matures.

  3. Prune for Size

    If your hydrangea has outgrown its space and you need to prune it, you can prune away select branches to curtail its size. Prune away select branches all the way to ground level or to a main stem, but make sure to retain some healthy branches to avoid losing all the flowers. A bigleaf hydrangea can be pruned back by one-third of its total mass, but harsher pruning will weaken the shrub and cause it to languish for a season or two.

    Tip

    Bigleaf hydrangea is the variety most susceptible to winter bud injury. If you live in an area with severe winters, you might need to offer it some protection. Tying the branches together and wrapping them with burlap can help the plant survive winter. Remove the burlap when the buds begin to swell.

How to Prune Smooth Hydrangea (H. arborescens)

Smooth hydrangea, including the popular cultivars H. arborescens 'Grandiflora,' 'Annabelle', and 'Incrediball', doesn't usually have any problems blooming, though its white flowers aren't as showy as we normally expect from hydrangeas. It's a round shrub with leaves that are somewhat rounded with a pointed end, paler on the underside than on the top. Blooming on new wood, smooth hydrangea does well with fairly aggressive pruning.

The Spruce / Letícia Almeida

  1. Remove Dead or Injured Branches

    This shrub blooms on new wood, so pruning should be done in early spring to ensure plenty of growth for flowers. Begin by removing any branches that have been injured or killed over the winter. These branches should be removed back to the main stem or even to ground level.

  2. Trim for Shape

    Additional branches can be lightly trimmed to shape the plant and retain its rounded shape. This kind of light pruning produces a large shrub with many small flower heads. "Light trimming" in this case means removing as much as one-third of each stem's length.

  3. Prune Hard for Large Flowers

    Hard pruning of a smooth hydrangea ( 12 to 18 inches from the ground) often creates a shrub that produces fewer, but much larger flower heads. These flowers may be so large that they require propping.

How to Prune Panicle (Peegee) Hydrangea (H. Paniculata)

Also known as peegee hydrangea, panicle hydrangeas produce football or cone-shaped flower clusters in mid-to-late summer. The flowers start out white, cream, or green and slowly turn pink, drying and remaining on the plant long after the leaves have fallen. Panicle hydrangea blooms on new wood; it accepts—and even prefers—fairly heavy pruning.

  1. Deadhead Spent Flowers

    During the growing season, you can deadhead the flowers (remove spent flowers) as they fade. This often helps prolong the bloom season as the plant puts more energy into continued blooming.

  2. Prune Lightly to Maintain Shape

    As soon as the flowers become unattractive, clean up the overall shape of the plant with selected pruning of branches that spoil the shrub's aesthetics. Panicle hydrangea makes for an attractive shrub even after flowering is complete.

  3. Do Hard Pruning in Late Winter or Early Spring

    Flower buds occur on new spring growth with this shrub. Some hard pruning of individual stems in late winter or early spring not only will keep the plant from becoming overgrown but also will encourage healthy growth and flowers. Panicle hydrangeas can be pruned by 1/3 of their total mass without damage to the plant. This is best done by pruning out smaller wood all the way to ground level, leaving only the larger stems—which can also be partly trimmed back if needed to maintain size.

    How to Prune Mountain Hydrangeas

    Mountain hydrangeas are small flowering shrubs with narrow, pointed leaves and flattened flower heads. This plant is sometimes confused with Hydrangea macrophylla because of their similar flowers. However, this type doesn't have the big leaves of Hydrangea macrophylla. Pruning should be done cautiously—or not at all, if not required to control the shrub's shape. Blooming occurs on old wood, and the plant's pruning needs are minimal.

  4. Remove Dead or Dying Stems in Early Spring

    Any dead or winter-damaged stems can be removed all the way to ground level with pruners in early spring, before new growth has started

  5. Prune for Shape

    If major pruning is necessary, wait until the shrub has finished flowering to trim back stems to a pair of healthy buds, using bypass pruners. This is not a shrub that always requires annual pruning.

How to Prune Climbing Hydrangeas

The stunning climbing hydrangea is the type you see slowly making its way up a tree or other support. Rather than a classic shrub, it is a woody vine and it normally requires little to no pruning except to control its size. This plant flowers on old wood grown during the previous season, so any major pruning you do should be done immediately after the plant flowers.

  1. Prune to Control Size

    Once climbing hydrangeas become established, they can grow quite vigorously and might need occasional hard pruning to set boundaries for the coming season. Do this pruning immediately after the plant flowers. Most flowers occur at the top of these plants, so side trimming will have less impact on the plant's appearance.

  2. Special Pruning to Rejuvenate a Neglected Plant

    Neglected, overgrown vines can be cut back to ground level in early spring to rejuvenate the plant. However, you can expect this to reduce flowering fairly dramatically for one or two seasons.

How to Prune Oakleaf Hydrangeas (H. quercifolia)

Oakleaf hydrangea is easily recognized by its oak leaf-shaped foliage. Because its major attraction is the foliage, any loss of blooms is less disappointing than in most other hydrangea varieties. Oakleaf hydrangea flowers on old wood and major pruning should occur immediately after it has finished flowering. Be somewhat cautious when pruning an oakleaf hydrangea—prune is done to control size or shape, not to stimulate new growth.

The Spruce / Adrienne Legault

  1. Prune Out Winter Dieback

    Inspect your shrub in the early spring before growth has begun. If your shrub has experienced winter dieback, prune the stems back to below the point of injury. Further pruning should wait until the plant has finished flowering.

  2. Prune for Shape

    Oakleaf hydrangea blooms on old growth, so any hard pruning that's required should be done immediately after it has finished flowering. Use sharp bypass pruners to remove branches that interfere with the desired shape of the shrub. This variety is not fond of heavy pruning, so never remove more than one-third of the plant's total mass, and don't feel obliged to prune at all unless it is essential to maintain the plant's size or shape. Cut selected stems back to just above the point where they meet the main stems.

How to Dry and Preserve Hydrangea Flowers

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  1. Guide to Pruning Hydrangeas. University of Maryland Extension

HOW TO PROPERLY CUT IN SPRING

The question of pruning hydrangeas in spring never loses its relevance. We have collected all the useful tips and provided them with diagrams so that the process is correct and the result pleases all summer.

Hydrangea is one of the most beautiful and fairly easy-to-care shrubs. However, the question of the correct pruning of hydrangeas in the spring never leaves the top of the most discussed topics. The brevity of the terms also warms it up - pruning must be carried out before active sap flow, i.e. when the plant is just waking up. In the Urals, this time (depending on the weather) falls on March-April. If you are late, you need to wait for the leaves to appear, and then trim as carefully as possible.

Important! Pruning must be systematic. For some varieties of hydrangeas, it is shown throughout the season. For others, the size of the inflorescence depends on it (regularly cut off - the inflorescences will be large, let the bush thicken - wait for the flowers to grind). And for almost all varieties, it is shown to form a beautiful dense crown of a shrub.

There are three pruning approaches that determine the timing and extent of flowering
  1. Short cut. We leave 2-3 kidneys. Thus, we achieve later flowering and the largest possible inflorescences.
  2. Medium cut. We leave 3-4-5 kidneys. Flowering occurs on time in accordance with the variety. In this case, the size of the flower brush will be large or medium, and flowering will be plentiful.
  3. Long cut. We remove from above from 3 to 5 internodes. We provide early flowering, an increase in the number of inflorescences with a decrease in their size.

All hydrangeas need pruning - both those that are planted in the ground and those that live in containers

General procedure for pruning hydrangeas

After a suitable day is chosen, we act according to the algorithm:

What kind of pruning does your hydrangea need?

What kind of pruning your hydrangea needs is determined by its type.

Examples of pruning different types of hydrangeas

  • Tree and paniculate hydrangeas bloom on the shoots of the current year. For tree hydrangea, the earliest dates (March) will be optimal, since it grows more slowly than paniculate, and it needs time to form young shoots. For paniculate hydrangea, pruning in April is suitable.
  • Large-leaved hydrangea blooms on last year's shoots. It should also be cut off in the early stages, but according to a special scheme - not like a tree. In addition, do not be too zealous: in large-leaved hydrangeas, only old dried inflorescences are removed, as well as weak shoots that have not endured the winter well.
    • Hydrangea pruning

    Hydrangea pruning

    1. Removal of spherical inflorescences.
    2. Removal of broken, dead ends of branches.
    3. Complete removal of old branches.
    4. Cutting of null shoots, incapable of flowering, which only take away strength from a flowering bush.
    5. Shortening of last year's shoots to a length of about four pairs of strong buds.
    Hydrangea pruning

    Pruning panicled hydrangea

    1. Removal of cones.
    2. Cut dried branches.
    3. Cut branches with fading growth.
    4. Shortening of shoots for the growth of large young inflorescences.
    5. Removal of excess shoots to avoid thickening.
    Hydrangea pruning

    Pruning large-leaved hydrangea

    1. Preservation of new shoots that did not bloom.
    2. Removing flowering branches only.
    3. Pruning of large shoots up to the outgoing new branch.
    4. Cut of dead, frozen, damaged branches.
    5. Cut of perennial branches.
    6. Cut small weak shoots.

    And remember: all your efforts were not in vain: the reward will be magnificent hydrangeas that will delight you all summer long!

    If you have not yet decided on the choice of hydrangeas, welcome to our catalog!

    Proper pruning of hydrangeas: subtleties and nuances of implementation

    Lush and proud hydrangea, pleasing to the eye with its luxurious flowers, can decorate any garden. But in order for the bush to look aesthetic and attractive, it needs periodic pruning.

    We will tell you when and how to do it, how spring pruning differs from autumn pruning, and how best to do this procedure in autumn.

    Timing and types of hydrangea pruning

    Hydrangea pruning is carried out both in spring and autumn. Spring is the time for cardinal haircuts and the formation of a bush. And at the end of the season, when nature falls asleep, and the plants are preparing for winter, there is no need to radically cut hydrangeas. Now it is important for us to thin out the bush and free it from diseased, dried and improperly growing shoots.

    Autumn pruning is carried out late, usually after leaf fall, because in September the plant changes color and is as beautiful and charming as in summer.

    There are several types of correct pruning for hydrangeas.

    1. Traditional annual pruning in order to obtain a stronger and more abundantly flowering plant.
    2. Formative pruning, which allows you to give the bush the desired configuration and optimally position the skeletal branches.
    3. Sanitary cleaning, which is the removal of old and damaged shoots, dry inflorescences.
    4. And finally, the rejuvenation of hydrangeas with cardinal pruning, which is carried out on aging or badly damaged bushes.

    Features of autumn pruning of hydrangeas

    Although the main part of the work takes place in the spring, pruning of hydrangeas in the autumn is also a must. It is needed in order to divide all the work on the formation and improvement of the plant into two periods. In this case, the hydrangea will endure the entire procedure safely.

    When pruning hydrangeas in autumn, you need to pay attention to old, damaged branches, as well as those that grow inside the shrub. They are removed, but young shoots are not touched in the fall. Also, shoots are cut almost to the ground, which for some reason were broken in the summer.

    The air temperature during this period should be plus 5-10 degrees. For different regions, this is the beginning - the end of October.

    The further north the region is located, the more gentle pruning of the plant should be in autumn, since hydrangea does not like severe frosts, and shortened branches will be less protected from cold temperatures. This is especially true of large-leaved hydrangea, which is thermophilic. The remaining species are considered relatively frost-resistant.

    Important! It is not customary (especially in cold regions) to carry out autumn pruning of the plant for the first three years, since the seedling needs strength to withstand and survive the adverse winter conditions. During this period, only forced sanitary cleaning is done.

    In the southern regions in autumn, you can act more decisively with the expectation of the next year. Experts believe that in warm climates, autumn pruning is even more preferable.

    All varieties of hydrangeas have their own specifics for autumn pruning.

    Peculiarities of hydrangea pruning by species

    All varieties of hydrangeas have their own specifics of autumn pruning.

    1. Panicle hydrangea. The shrub blooms on the shoots of the current year, so don't be afraid to accidentally cut off a branch with flower buds. In autumn, you need to remove flower stalks, cut off dry and lodging branches.
    2. Tree hydrangea. This species also blooms on the current year's shoots. The rules of the autumn haircut coincide with the pruning of the paniculate hydrangea. It is necessary to remove flower stalks, cut out dubious, broken and dry branches.

    Let's dwell separately on pruning large-leaved hydrangea. The haircut of this beauty in the fall should be carried out carefully, remembering that she blooms on the shoots of last year. That is, right now we can accidentally cut off all the future beauty.

    All the large-leaved hydrangea needs now is the removal of peduncles and unproductive branches.

    Learn more