Viburnum Opulus 101: How to Grow This Stunning “Snowball Bush”
Viburnum opulus is a species of plant from the Adoxaceae family and the “Roseum” is the most popular cultivar and has showy globe-like blooms that have earned the plant the nickname “snowball bush”.
Expect dozens and dozens of white pom-pom blooms from May into June, but the interest is maintained throughout the year as the foliage turns a delightful reddish-purple in autumn.
- A reliable space filler: Viburnum opulus grows up to 4 metres high and wide.
- Full hardy, fast-growing and easy to maintain.
- Grow as hedging, screening or a feature, the snowball bush is versatile and eye-catching.
Other cultivars of Viburnum opulus have flatter flowerheads but are otherwise very similar.
Viburnum opulus grows to:
Height: Up to 4m (13′)
Width: Up to 4m (13′)
Deciduous: Loses its leaves in the winter
Reaches full size in around 7-10 years
Easy to grow but mature specimens will need a yearly prune
Europe, North Africa and Asia
Moderately fertile soil that is free-draining
Grow in full sun, partial sun, dappled or in light shade
US zone 3-8 and hardy in all parts of the UK
Water & Feed
Water regularly until established and then only in hot summer conditions
Hydrangea, azaleas and rhododendrons, lilac
Ideally when the soil is warm in autumn or spring but also possible in the summer
Typically in May and June but early bloomers may put on a show in late April
Viburnum Opulus Growing Guide: How to Grow Opulus
How and When are Viburnum Opulus Sold?
It can take 2-4 years before viburnums produce flowers so look for plants that are mature enough, which will typically be those in 5 litre+ pot sizes.
Where is the best location for viburnum opulus?
Grow in a sheltered or exposed spot, viburnums aren’t fussy. They perform best in full sun, dappled, partial and light shade.
Some surprise and bloom reliably in full shade but some sunlight is preferable.
This shrub will need some space to grow into so keep away from soil filled with roots.
How should the soil be prepared?
This shrub prefers moderately fertile soil that’s free draining so dig in organic matter to improve the ground conditions if required.
Apply a thick layer of fertile mulch each year for best results.
How much water or fertiliser do viburnum opuluses require?
Fertiliser isn’t required if a yearly mulch is put down.
Water well in the first year until the roots are established and then only when needed during heatwave conditions.
Potted shrubs will require more frequent watering, especially during the summer months.
How tall and wide will this shrub grow?
In normal conditions, a viburnum opulus can reach over 4 metres tall and wide but the potential depends on the ground conditions and amount of sunlight.
How should viburnum opulus be pruned and deadheaded?
There is no need to deadhead this shrub.
Also, young viburnums shouldn’t be pruned at all as it will only slow down their progress.
Pruning option 1: Mature specimens can be pruned by cutting off one-third of the growth and forming a neat, rounded shape where possible. This is best done immediately after flowering has finished.
Pruning option 2: Alternatively, prune mature plants yearly by removing no more than 1 out of every 5 stems. Look for weak branches or those that are out of shape, prune off at the base after flowering to encourage new shoots.
Viburnum opulus will recover quickly from an aggressive prune and a wayward shrub can be pruned right down to the crown.
Do viburnums suffer from any pests and diseases?
Viburnums are tough shrubs that resist most pests and diseases.
Watch out for:
Powdery mildew on the leaves – this can be remedied by improving the airflow around the plant, removing affected leaves and by avoiding overhead watering.
Viburnum Beetle – telltale signs are lacy looking leaves resulting from the beetle eating its way around the leaves. Thomson & Morgan have published a helpsheet including photos here.
When does viburnum opulus bloom and how long for?
More and more shrubs are coming into bloom earlier due to climate change. The University of Cambridge recently reported that many plants in the UK are flowering a full month earlier than they did 35 years ago.
Traditionally, this shrub flowered in May and June.
You may see blooms as early as late April.
The flowers last a few weeks and aren’t damaged easily by wind or rain.
Can viburnum opulus be propagated?
The best way to propagate viburnum opulus is by softwood stem cuttings taken during the growing season.
Pick an overcast day when the plant won’t be stressed and water well the night before.
Take a 6-12″ healthy stem from a vigorous part of the plant and dip in rooting hormone before inserting into a suitable potting medium and covering with plastic, such as a drinks bottle.
Keep the cutting out of direct sunlight and the medium moist at all times.
The rooting time is around four weeks.
Hardwood cuttings can be used instead, but the success rate is lower and may take longer.
Is viburnum opulus toxic or harmful to humans and pets?
No toxicity has been reported.
Is this shrub beneficial to wildlife?
Viburnum opulus is very beneficial to bees, butterflies, other pollinators, birds and beneficial insects.
Can viburnums be grown in pots?
Viburnum opulus is a fairly large shrub, reaching up to 4 metres in height, and while it’s possible for a gardener to grow in a container, it might not be practical.
The best option is Viburnum opulus variety “Bullatum”, which reaches 60cm (2′)
Smaller, dwarf varieties such as Mapleleaf viburnum and David viburnum might be more suitable.
While mature viburnums are fairly drought tolerant in woodland and suitable gardens, they will need more frequent watering if grown in pots.
At a Glance:
Here are 10 key points anyone growing viburnums opulus should consider:
- Expect a showy display of white, fluffy blooms in spring which is complimented by reddish-purple foliage in autumn.
- Viburnums are unlikely to flower in the first 2-4 years so buy mature plants where possible.
- They aren’t fussy about exposure but prefer sunlight, partial shade or dappled shade.
- They tolerate a wide variety of soil types.
- Water well until established when they should be fully drought tolerant, except potted viburnums which will require consistent watering.
- Don’t prune young plants but once established prune yearly, either by removing one-fifth of the stems at the base or by pruning the entire plant by up to a third.
- Viburnums will usually recover from a very hard prune.
- They will respond well to yearly mulch but don’t need fertilising beyond this.
- Opulus is the showiest viburnum but there are several similar varieties.
- They make lovely cut flowers!
Viburnum Companion Plants
Another option is to mix mid-size shrubs around the viburnums.
Consider these plants as they make for great companion plants:
Other varieties of viburnum opulus have flatter and less showy blooms but are worth considering.
Hydrangea arborescens “anabelle” is a completely different species that flowers after viburnums but also has round globe-like blooms.
Problems, Pest and Diseases
Viburnum shrubs are tough and require little care and attention once established, but here are solutions to some common problems:
1) Viburnum Not Flowering
This is usually caused by one of the following:
- The plant is still young and isn’t mature enough to produce blooms. This shrub needs up to four years of growth before it can bloom, hence why gardeners should buy established plants from reliable growers.
- Too much shade – once established, this shrub should bloom reliably; if they don’t, it could be due to a lack of sunlight.
- Too much water – viburnums only need watering if potted or during the first few months after planting. They dislike soggy conditions and may refuse to bloom at all if grown in waterlogged soil.
2) What is Eating Viburnum Leaves?
Shredded leaves are a tell-tale sign of a viburnum beetle infestation.
3) Leggy Stems With Few Flowers
Once established, viburnums grow reasonably quickly and can become leggy and sparse if not pruned yearly.
Hannah’s Viburnum Pro Tip
Here is a quote from Hannah, our co-founder:
Viburnums don’t have a great reputation in the UK, they are often used in landscaping around residental areas but don’t be put off, the “opulus roseum” is the showiest cultivar and the fluffy pom-pom flowers bloom reliably.
This shrub is also incrediably easy to grow and is usually self-reliant once established.
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More From Daniel Woodley:
This guide to growing viburnum opulus for spring colour was created by Daniel Woodley here at DIY Gardening and was last updated in February 2022.
Daniel is a keen gardener who also manages a large residential landscape in addition to his own mid-size garden.
He also enjoys experimenting with vegetables and fruits in his garden but with varying success!
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