Viburnum Care Guide: How to Grow and Maintain Viburnum Shrubs

Growing Viburnums in NZ

Viburnums are versatile, hardy shrubs that thrive in New Zealand gardens, offering attractive foliage, fragrant flowers, and vibrant berries. Well-suited to a variety of climates and soils, they provide year-round interest and can be used for hedging, screening, or as specimen plants. Proper planting, watering, and pruning help ensure healthy growth and abundant flowering.

Popular Viburnum Varieties

Viburnums are popular garden shrubs in New Zealand, valued for their attractive foliage, fragrant flowers, and colourful berries. They suit a variety of garden styles and climates, offering year-round interest through seasonal blooms and vibrant fruit. Whether you want evergreen screening or striking seasonal colour, there’s a Viburnum variety to enhance your garden.

• Viburnum tinus – Evergreen shrub with glossy leaves and clusters of white flowers followed by blue-black berries.
• Viburnum opulus (Snowball Viburnum) – Deciduous shrub known for its large, white, globe-shaped flower clusters.
• Viburnum davidii – Compact evergreen with dark green leaves and bright blue berries.
• Viburnum burkwoodii – Semi-evergreen shrub with fragrant white flowers in spring.
• Viburnum plicatum Lanarth – A deciduous shrub featuring layered, horizontal branches adorned with fragrant white flowers in spring and vibrant autumn foliage.
• Viburnum plicatum (Doublefile Viburnum) – Deciduous shrub with layered horizontal branches and showy white flowers.
• Viburnum Dense Fence – A fast-growing, compact evergreen shrub ideal for creating thick, attractive hedges and privacy screens.

The Plant Company has an amazing range of Viburnum varieties which are supported with fantastic information to help you succeed.

Deciduous Viburnum

Deciduous Viburnums, such as Viburnum opulus and Viburnum plicatum, lose their leaves in winter but offer stunning autumn colour and attractive berries. These varieties are well-suited for creating seasonal interest in your garden, providing a burst of colour in autumn and visual interest with their bare branches in winter. The berries they produce are often a favourite of birds, adding an element of wildlife attraction to your garden. Additionally, the changing foliage colours throughout the year provide a dynamic backdrop that can enhance the overall aesthetic of any garden space.

Evergreen Viburnum

Evergreen Viburnums are popular for providing year-round foliage, making them an excellent choice for creating privacy screens or hedges that remain lush throughout the seasons. Some common varieties include Viburnum tinus and Viburnum davidii, both of which are known for their glossy leaves and clusters of attractive flowers. These species are particularly valued for their ability to add texture and colour to the garden during the winter months when many other plants are dormant. Their ability to withstand a variety of climates and soil conditions adds to their appeal, making them a staple in many gardens.

Planting Viburnum Shrubs

The first step in growing healthy Viburnum shrubs is proper planting. By ensuring the right conditions from the start, you set the foundation for vibrant and flourishing plants. Here are some tips to get you started, from choosing the perfect location to executing the planting process effectively.

Choosing the Right Location

Viburnums thrive in well-drained soil and prefer full sun to partial shade. Choose a location that receives at least six hours of sunlight daily to ensure optimal growth and flowering. While they can tolerate a variety of soil types, amending poor soil with organic matter can greatly enhance their performance. It's also essential to consider the mature size of the variety you choose, ensuring there is ample space for the plant to grow to its full potential without overcrowding other plants.

Planting Steps

• Before planting, add organic matter such as compost to improve soil health and fertility. This step is crucial for ensuring the roots have the best environment to establish and thrive.
• Dig a hole twice as wide and as deep as the root ball. This gives the roots plenty of space to spread and establish, promoting healthy growth from the start.
• Place the Viburnum in the hole, ensuring that the top of the root ball is level with the soil surface. Backfill with soil, pressing gently to remove air pockets. This helps avoid issues such as root rot and ensures the plant is securely anchored.
• After planting, water the shrub deeply to help settle the soil and establish roots. Proper watering is critical in the initial stages to reduce transplant shock and encourage root development.
• Taller plants should be staked for additional support.

Viburnum Care and Maintenance

Once planted, Viburnum shrubs require regular care to thrive. By following a consistent care routine, you can ensure your Viburnums remain healthy and vibrant throughout the seasons. Here are essential tips for maintaining your Viburnum plants, from watering to pruning, ensuring they reach their full potential.

Watering Viburnum

Consistent watering is crucial, especially during the first growing season when the plant is establishing its root system. Water your Viburnum deeply once a week, allowing the soil to dry slightly between waterings to prevent overwatering, which can lead to root rot. During hot, dry spells, increase the frequency to prevent stress, as dehydration can cause leaf drop and reduced flowering. Mulching around the base of the plant can help retain moisture and regulate soil temperature, providing a more stable environment for root growth.

Pruning Viburnum

• Pruning is an essential aspect of Viburnum care. Not only does it help maintain the shrub's shape, but it also encourages healthy growth and flowering, ensuring your Viburnums remain attractive and vigorous.
• Prune Viburnum shrubs in late winter or early spring before new growth begins. This helps remove any dead or damaged wood and shapes the plant for the coming season, allowing for the most productive growth period.
• Use clean, sharp pruners to make cuts just above a bud or lateral branch. Remove any crossing or crowded branches to improve air circulation, which can help prevent disease and promote healthier growth patterns.

Feeding and Fertilizing

• Feed your Viburnum shrubs with shrub fertilizer in early spring. This provides the nutrients they need for robust growth and abundant blooms, supporting their energy needs as they emerge from dormancy. Follow the package instructions for application rates and frequency to avoid over-fertilization, which can lead to excessive foliage growth at the expense of flowers. Periodic soil testing can help you determine any nutrient deficiencies and adjust your fertilization regimen accordingly.

Viburnum Flowering Season

[Viburnums] are renowned for their stunning blooms, which vary by species. The flowering season is one of the highlights of growing Viburnums, providing a burst of colour and fragrance that enhances any garden.

Bloom Time

Most Viburnum varieties flower in spring, although some, like Viburnum tinus, can bloom in late winter. The blooms are typically fragrant and attract pollinators such as bees and butterflies, adding life to your garden. This pollinator activity not only supports the health of your garden ecosystem but also contributes to the overall biodiversity of your area. Knowing the bloom time of your chosen Viburnum can help you plan a succession of flowering plants for continuous colour throughout the year.

Encouraging Flowering

To ensure a prolific flowering season, maintain consistent care throughout the year. Proper watering, feeding, and pruning will all contribute to a vibrant display of flowers. Additionally, ensuring that your Viburnums receive adequate sunlight and are protected from harsh winds can enhance flower production. Deadheading spent blooms can also encourage further flowering, extending the bloom period and keeping the plant looking tidy.

Viburnum Pests and Diseases

While Viburnums are generally hardy, they can be susceptible to certain pests and diseases. Understanding the potential threats and knowing what to look for can help you manage these issues effectively, keeping your plants healthy and thriving.

Common Pests

• Aphids: These small insects can cause distorted leaves and reduced growth by sucking the sap from the plant. Control them with insecticidal soap or a strong spray of water to dislodge them.
• Scale: Scale insects appear as small, immobile bumps on stems and leaves. Use horticultural oil to treat infestations, which suffocates the pests without harming the plant.
• Viburnum Beetle: This pest can defoliate Viburnum shrubs quickly, causing significant damage if left unchecked. Handpick beetles and larvae or apply insecticides if necessary, monitoring regularly for signs of re-infestation.

Common Diseases

• Powdery Mildew: Characterized by a white, powdery coating on leaves, this disease can reduce vigor and flowering. Improve air circulation by pruning and apply fungicides if needed to control outbreaks.
• Leaf Spot: Causes brown or black spots on leaves, potentially leading to premature leaf drop. Remove affected leaves and apply a fungicide to prevent further spread, maintaining good garden hygiene to reduce the likelihood of recurrence.