Pruning viburnum – [How and when to prune]

Viburnum tinus is an evergreen shrub that belongs to the Caprifoliaceae family. Since it is native to the Iberian Peninsula, it is very popular in gardens in the Mediterranean region. One of the most outstanding attractions of this shrub is the spectacularity of its flowers, of a beautiful white color (sometimes pink). As you can imagine, in this post we will dedicate ourselves to an in-depth analysis of everything related to pruning Viburnum shrub. How and when to prune, when to do a heavy pruning and a brief analysis of some of the most common varieties of Viburnum.

As we well anticipated in the previous paragraph, there are many species of Viburnum shrubs. Some of the best known are Viburnum davidii, Viburnum opulus, arrowwood viburnum, Korean spice viburnum, among others. Our post will give an overview of Viburnum shrub pruning, although at the end we’ll take a moment to briefly discuss a few species in particular.

1. Tools needed for pruning

When it comes to pruning viburnum, having the right tools can make the task more efficient and help you achieve better results. Here are some essential tools you may need for pruning your viburnum:

• Pruning Shears: Pruning shears have one sharp blade and one opposing blade. Pruning shears are used to cut small and medium branches.

• Pruning Saws: Pruning saws are tools used to cut larger branches. Pruning saws have a serrated blade and an ergonomic handle for a comfortable grip. Pruning saws are used to cut larger branches larger than 2.5 cm in diameter.

• Hand Shears: Hand shears are tools used to cut small shoots and smaller branches. Hand shears have sharp blades and are used to cut shoots up to 1.3 cm in diameter.

• Gardening Gloves: Gardening gloves are necessary to protect the gardener’s hands. More than key point when pruning plants with thorns as in the case of rose bushes.

• Safety glasses: Safety glasses are necessary to protect the gardener’s eyes from shavings, dust and twigs.

• Ladder: Depending on the size of your juniper you may or may not need a ladder.

Keep in mind that you should disinfect all cutting tools before starting pruning. This will reduce the risk of spreading diseases between plants in your garden. Next we will see some methods to do it quickly and easily.

1.1 How to care for and disinfect your tools

Taking care of your tools will allow you to extend their life. While disinfecting them will help you avoid a possible spread of diseases from one plant to another.

Let’s start by quickly reviewing the care:

• Use the right tool for a job and avoid twisting or straining it.
• Clean and oil tools regularly by wiping an oily cloth on blades and other surfaces.
• Keep cutting edges sharp by regularly using an oilstone.
• Wooden handles should be varnished or regularly treated with linseed oil to keep them from cracking or splintering.

I personally know three simple methods to disinfect your tools, and they are the following:

• Method 1: rub the scissors blades with a cloth dipped in alcohol (ethanol). After cleaning, allow the tool to sit for a couple of minutes for maximum disinfection efficiency.
• Method 2: prepare a mixture 1/9 of chlorine and water (one part of chlorine and 9 of water). Then soak the scissors for half an hour in that mixture. After those 30 minutes you can start pruning.
• Method 3: this third method is effective but from my point of view not so recommended. Here what you should do is pass the blade for a few seconds through a flame. This will disinfect but also burn the blade.

2. When to prune viburnum

You already know what tools you should have on hand to carry out pruning, it is time to analyze what is the most appropriate time to carry out this task. For this case we will analyze what kind of pruning you can do at each time of the year.

2.1 Viburnum pruning in spring

Spring is generally considered the best time to prune many viburnum species. Especially to carry out light pruning, for hard pruning it is not the best time. During the spring it is best to prune soon after its flowering period has finished.

By choosing spring to prune you allow the plants to develop new growth quickly. In addition it is guaranteed that no flower buds are removed for the next year. This is because the viburnums usually place the cocoons in the old wood.

2.2 Viburnum pruning in late winter

During the winter you should prune just before new growth emerges. Keep in mind that pruning too early in winter could expose the plants to frost damage. If you are going to perform a hard pruning of a Viburnum, this is the most appropriate time to do so.

The advantage of pruning in winter is that it allows you to easily identify the structure of the plant and remove dead or damaged branches. In addition, pruning at this time stimulates vigorous spring growth and encourages abundant flowering.

2.3 Viburnum pruning in summer

Although the most common and recommended is to prune in spring or late winter, there are certain tasks that can be done in summer.

A clear example that merits pruning in summer is removing dead or diseased branches. Especially when it comes to diseased branches, it is always a good time to cut them. The sooner you cut, the more likely you are to prevent further spread of the disease.

In very neglected Viburnum also summer can be a good time to prune. At this time you should not perform very hard pruning, but a light and selective pruning can be done. This way when winter comes pruning should not be so hard.

2.4 Viburnum pruning in autumn

This is a time when we do not recommend pruning this shrub. The reason is simple, if you prune in autumn you will be stimulating the plant to generate new shoots, which can freeze with the first temperatures below zero.

What you can do in the fall is cleaning pruning. Eliminating diseased, dead branches or cutting old flowers. Always avoid performing important pruning in autumn.

3. How to prune viburnum

You already know which tools are needed and when you should prune your viburnum shrubs. It is time that we analyze how to prune, for this we will see some of the most common types of pruning that you must carry out.

3.1 Annual pruning necessary in a Viburnum

The important thing in viburnum pruning is to perform an annual pruning, so as not to leave the bush neglected and need a harder pruning. These practices help ensure the health, aesthetics, and longevity of the shrubs.

We will look below at the steps involved in regular maintenance pruning of the viburnum.

• Removing Dead, Damaged, and Diseased Branches: The first thing to do is check the viburnum for any dead, damaged, or diseased branches. Dead wood should be removed quickly by cutting it back to the branch neck or point of origin. Similarly, prune branches that show signs of damage or disease, making clean cuts in sound wood.

• Thinning of the crown: with this task what we are looking for is to improve the flow of air and the penetration of light inside the bush. In this way we reduce the risks of fungal diseases. Also promoting new and healthier shoots. To do this, you should cut the old and thickest branches inside the bush. When cutting each branch, cut just above the junction of a bud or side branch.

• Sucker and water shoot removal: As you may know, suckers are shoots that arise from the base of the viburnum that consume a lot of energy from the plant and detract from the plant’s appearance. This is why it is important that each year you take a moment to find all the suckers and cut them from the base of the suckers.

By performing these simple pruning tasks on your viburnum every year, you can keep it healthier, more attractive, and thriving. Extending its useful life and avoiding the need for harder pruning that can end up damaging the bush.

3.2 Hard pruning viburnum (overgrown)

While these shrubs should be maintained with regular light pruning each year, there are times when heavy pruning is needed. These prunings are drastic and suitable for rejuvenating neglected or overgrown viburnum plants.

The first thing you should do is assess the general health of the viburnum. Cut off all dead or diseased branches. It is important that you cut these branches down to solid wood or down to ground level, depending on the severity of the problem.

Once the dead or diseased branches have been cut, you should look for the oldest and highest branches. You must cut them all to a third of their height. This will encourage new growth from the bottom of the plant.

All other branches should be trimmed back to maintain a balanced shape and size. Make angled cuts just above a healthy bud or side branch junction.

After a hard pruning, it is key to provide abundant watering and proper care to support the recovery of the plant. Consider applying a balanced, slow-release fertilizer to promote healthy growth.

3.3 Prune viburnum into tree

Some species of viburnum admit pruning that tends to give it the shape of a tree. Some of the species are Viburnum carlesii or Viburnum plicatum.

This type of pruning should begin when the shrub is young. Select a viburnum with a single straight stem as the main trunk, cut back the other shoots or side branches at the height you want to start forming the tree.

As the trunk grows, remove any new side shoots that develop along the bottom of the trunk. This encourages upward growth and a more tree-like shape.

Over time, you should allow the upper trunk to develop several well-spaced side branches. In this way, what you should look for is that the viburnum forms a good cup.

Once you have the tree already formed (after a couple of seasons), subsequent pruning is limited to light maintenance pruning. It is important that you perform these maintenance prunings on a regular basis. Otherwise you will end up losing the shape of the tree.

Never fail to cut all the branches that come out from the bottom of the bush. These sprouts can end up being a competition from the main trunk, and it is something that we should not allow.

4. Pruning Viburnum – Different species

When it comes to pruning specific species of viburnum, there are certain particularities and considerations to keep in mind. While the general principles of pruning apply, understanding the unique characteristics of each species can help you achieve the best results. Here are some specific pieces of advice for pruning the following viburnum species:

4.1 Arrowwood Viburnum (Viburnum dentatum)

For the Arrowwood viburnum species, regular pruning is essential to maintain its shape and size. This species tends to produce quite a few shoots from the base, so you should remove them with each pruning. You should also perform a selective trimming of the older branches to promote air circulation and encourage new growth.

4.2 Viburnum Opulus Snowball

Viburnum opulus ‘Roseum’ is famous for its clusters of large, rounded white flowers. That is why it is known as Snowball viburnum, so that it retains its shape and also encourages its flowering, it is key to prune it after flowering. This is late spring or early summer.

The pruning they need is light, removing dead or diseased branches and trying to respect the structure of the bush. Only on occasions when the bush is very neglected is it necessary to opt for a stronger pruning.

4.3 Viburnum Bodnantense

One of the most appreciated characteristics of the Viburnum bodnantense are its beautiful pink flowers that bloom in winter. For this reason and taking into account that flowering occurs in old wood, it is necessary to be very careful with pruning.

It is important that you prune once the flowering is finished. In this way you will avoid removing flower buds from next year. Trim all dead or damaged wood, at the same time cut back the branches that grow untidy to respect the shape of the shrub.

4.4 Sweet viburnum (Viburnum odoratissimum)

Sweet viburnum is cherished for its lush foliage and fragrant flowers. Pruning this species is best done after flowering to avoid removing potential flower buds for the following season. Remove any dead, damaged, or crossing branches, and selectively prune to shape and maintain the desired size. Lightly tip-prune the branches if necessary to encourage bushier growth.

4.5 Viburnum Davidii

Viburnum davidii is a low-growing evergreen species with distinctive bluish-black berries. The pruning that you must carry out is minimal, the ideal is to leave it in its natural form.

With the regular pruning of each year you must eliminate the damaged, diseased or messy branches. Avoid heavy pruning, as it can negatively affect bush growth and berry production.

4.6 Korean Spice Viburnum (Viburnum carlesii)

Korean spice viburnum is loved for its fragrant pinkish-white flowers and colorful fall foliage. Like many viburnum species, pruning should be done once flowering has finished.

Light pruning once a year will suffice. It is important to conserve the branches of the previous year since the flower buds are produced from them.

4.7 Leatherleaf viburnum (Viburnum rhytidophyllum)

Leatherleaf viburnum is known for its large, leathery, evergreen leaves. It is essential that you avoid excessive pruning on this species of viburnum, as it can affect the shape of the viburnum and decrease its ability to produce leaves and flowers.

Pruning as in almost all these shrubs should be light. You should not neglect the Leatherleaf viburnum, otherwise you should resort to strong pruning that can affect it.

4.8 Chindo viburnum (Viburnum awabuki)

Chindo viburnum is a popular evergreen shrub with glossy leaves. It benefits from light pruning to maintain its shape and size. Regularly remove any dead or diseased wood and selectively thin out crowded branches to improve airflow and overall appearance. Avoid heavy pruning, as it may lead to a less dense and unattractive growth habit.

5. Viburnum pruning youtube

As we do with many of our posts, we have decided to end it with a Youtube video tutorial. In this case we have selected a video from the Pioneer PBS channel, watch it as it will help you to graphically understand much of what is analyzed in this post about pruning the viburnum bush.

More information:

• Viburnum info sheet – rockledgegardens.com.

• How to Care for a SWEET VIBURNUM – thdstatic.com.

• VIBURNUM CARE & CULTURE – oregonlive.com.

• Viburnum A Shrub for All Seasons – skh.com.