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How to prune hydrangea bushes


When to prune hydrangeas for best bloom

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Hydrangeas are one of the most popular blooming woody shrubs in Minnesota landscapes and, as you’d expect, people often ask how and when to prune these beloved shrubs.

Heading cuts redirect growth or shorten small branches. The high point of a heading cut should be about 1/4" above a bud.

Hydrangea paniculata, panicle hydrangea

Prune back stems to just above a fat bud — called a heading cut — in fall, late winter or spring. These plants have conical-shaped flower heads. I recommend leaving the dry, tan flower heads on the plant to provide some winter interest in your landscape, so I wait to prune these until late winter or spring. Some favorite panicle hydrangeas:

Hydrangea macrophylla, big leaf hydrangea This original Endless Summer inspired a large series of other H. macrophylla developed by Bailey Nurseries.

These plants produce buds in late summer to early fall (August-September) that will form next year’s flowers. So prune these shrubs after they finish blooming before August (again, make a heading cut).

An exception is the Endless Summer® The Original Bigleaf Hydrangea (H. macrophylla 'Bailmer' PP15,298) and other cultivars in the Endless Summer series from Bailey Nurseries such as Blushing Bride, BloomStruck® , Summer Crush®, and Twist ‘n’ Shout®.

The H. macrophylla bloom on last year’s wood and new wood that grows this year. So it will bloom whether you prune it or not. Protect H. macrophylla in winter from rabbit browsing on the stems with a large, 4-foot tall ring of hardware cloth.

The Endless Summer hydrangea made a huge splash on the Minnesota landscape plant scene because of its pink to blue color flowers (achievable with proper soil amendment) and because it blooms on old and new wood.

Hydrangea arborescens, smooth hydrangea

Let these plants grow a season or two before doing any serious "hard" pruning. Once the shrub is established and has a couple of growing seasons under its belt, prune these hydrangeas in the spring down to the ground, or not at all if you want a larger shrub. Flower buds will grow on this season’s growth or new wood.

Some favorite smooth hydrangeas: 

Hydrangea petolaris or climbing hydrangea

This tough, gnarly vine needs little to no pruning ever, except for removing any dead wood that develops.

Plant this vine in full sun on a solid trellis or fence where you want a long-living, dense screen. It is a dickens to get rid of once it gets established.

Hydrangea paniculata ‘Limelight’ Quick Fire® hydrangea. Notice the wall color matches the late summer bloom color. This was intentional! Annabelle, a tried-and-true fixture in Minnesota landscapes

Author: Julie Weisenhorn, Extension educator, horticulture

Reviewed by Debbie Lonnee, Product Development Manager, Bailey Nurseries.

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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 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.

    Learn more