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mathias nurseries leylandii hedges

How Far Do Leylandii Roots Spread?

Leylandii hedges, known for their dense foliage and rapid growth, are a popular choice for gardeners seeking privacy, windbreaks, or decorative green screens. However, their success largely hinges on a well-developed root system. 

Left to grow, some Leylandiis have been known to reach heights of 30 metres, with widths of 8 metres. A Leylandii will continue to grow at a rate of around 90 cm a year. 

Of course, it’s easy to stop the spread of a plant overground, but under the surface is another matter. When you bring your Leylandii hedge home, knowing how big its roots will grow can help you plan the perfect place to plant it to give it the best chance of success.

In this article, we'll look at what happens beneath the soil, exploring the root structure of Leylandii hedges, the factors influencing root spread, and important considerations for planting near structures or other plants. Armed with this knowledge, you can make informed decisions to ensure the health and longevity of your Leylandii hedge.

What Is the Root Structure of Leylandii Hedges

Understanding the root structure of Leylandii hedges is crucial to ensure they thrive in your garden. These hedges possess a relatively shallow and wide-reaching root system, which makes them both adaptable and vulnerable. 

Leylandii hedges generally extend no deeper than 60 cm. When planted in clay soil, roots are typically even shallower. This characteristic allows them to absorb water and nutrients from the topsoil quickly.

The lateral root spread of Leylandii hedges can be extensive, reaching up to three times the width of the hedge's canopy. This expansive network helps stabilise the hedge and gather resources efficiently.

Leylandii hedges at Mathias Nurseries

What Factors Influence Leylandii Root Spread?

Several factors can influence the root spread of Leylandii hedges. Understanding these factors will help you plan your garden effectively and maximise the health of your hedge:

Soil Type

Soil quality plays a crucial role in determining how far Leylandii roots will spread. Well-draining soil encourages healthy root development, while waterlogged or compacted soil can restrict it.

Water Availability

Leylandii roots grow towards sources of moisture. If they're regularly watered or planted near a water source, their roots might not need to spread as far.


Nearby structures and other plants can influence root spread. Leylandii roots may compete with neighbouring plants for water and nutrients, and they may also be attracted to any available gaps in the soil near structures.

If a Leylandii is planted close to other plants, the hedge’s roots will absorb the majority of the water in the area, leaving very little for anything growing nearby. 

How Much Space Do You Need for Leylandii Roots?

When you are planting Leylandii hedges near walls, buildings, or other plants, it's essential to consider these factors to promote healthy growth and avoid potential problems:


Give your Leylandii hedge plenty of space. Keep them far enough away from structures like buildings or fences. A general rule of thumb is to plant them at least 2-3 feet away from these structures to prevent root damage and ensure proper air circulation.

While a well-kept Leylandii shouldn’t cause problems for a building, the roots of a larger plant could, particularly if it's next to an older property. 

When planting near a building, it’s important to keep the hedge trimmed. Pruning your hedge twice a year can help reduce the spread of its roots. 

Read our blog on cutting your hedge for advice.


Think about the distance you’re planning your Leylandii from other plants in the area. Competition for resources can lead to stunted growth or unhealthy hedges. Plan your garden layout to minimise resource competition.

Root Barriers

In cases where Leylandii roots might interfere with structures or neighbouring plants, you may want to consider installing root barriers. These physical barriers can help control root spread and protect other garden elements.

Soil Management

Ensure your Leylandii hedge is planted in well-draining soil to encourage healthy root development. Regular soil testing and amendment can be beneficial.

Adding a leaky hose will ensure you provide enough water for your Leylandii at all times. Read more on watering your hedge in our blog. 

Leylandii Hedges at Mathias Nurseries

The root system of Leylandii hedges is a vital component of their growth and overall health. Understanding their shallow, wide-reaching root structure and the factors influencing root spread is key to successful garden planning. 

By considering the factors mentioned above and taking appropriate precautions, you can ensure your Leylandii hedge not only thrives but also coexists harmoniously with other garden elements and structures. For more information, please read the guide to Leylandiis on our blog. 

If you need more advice on planting your Leylandii, get in touch and speak with our team of experts today. We’re always available to help you make the right decisions when choosing, planting, or maintaining your hedge. 

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