The Ultimate Guide to Planting a Thuja Plicata Hedge (Western Red Cedar) in the UK

If you’re after a fast-growing, evergreen screen with a lovely fragrance, a Thuja plicata hedge is hard to beat. Thuja plicata, better known as Western Red Cedar, is a conifer that looks similar to green Leylandii and grows at a similar pace. It has dark green foliage that can turn a warm bronze in cold winters, and when you crush the leaves you get a pleasant, fruity scent. Unlike some conifers, Thuja plicata will often re-shoot even when cut back into old wood, which makes it a forgiving hedge to keep in shape.  See our YouTube video of a good example of a Thuja plicata hedge to see what results you can end up with.

In this guide, we’ll cover everything you need to know about Western Red Cedar hedging plants — from spacing and planting through to pruning, soil, and choosing the right variety.

Why Choose Western Red Cedar Hedging Plants?

• Fast, Manageable Growth: Reaches up to 75–80 cm (2’6″–2’8″) per year
• All-Year Privacy & Shelter: Dense, evergreen growth provides year-round screening
• Winter hardiness – Extremely hardy
• Works well as a windbreak
• Forgiving Pruning: Handles close trimming better than Leylandii and regenerates from light pruning into older wood.
• Aromatic Foliage: Crushing or trimming the leaves releases a pleasant, pineapple-citrus scent.
• Grows in almost any soil (aside from waterlogged ground)
• Thrives in both sunny and shady spots
• Filters out pollution – the dense foliage is one of the best types for filtering out pollution and particulates from roads

How far apart should I plant Western Red Cedar (Thuja plicata) to form a hedge?

Getting your Western Red Cedar spacing right makes a real difference to how quickly your hedge fills in. Plant your Thuja plicata hedging plants between 60cm and 1m (2–3ft) apart:

60cm (2ft) apart — the gaps close in faster, so choose this spacing if you want a dense hedge sooner.

1m (3ft) apart — you’ll still get an equally good hedge, it will just take roughly a year longer for the plants to knit together.

How Tall Will Thuja Plicata Grow?

One of the best things about Thuja plicata is how much control you have over its height. You can keep a hedge as low as 120cm (4ft), and it copes brilliantly with regular clipping. As a rule of thumb, keeping your hedge at 2–3m (6–8ft) or below makes trimming far easier than letting it grow taller.

Left to its own devices, Western Red Cedar will reach 20–35 metres (70–120ft), making a genuinely striking specimen tree if you’ve got the space.

How Fast Does Thuja Plicata Grow?

In good growing conditions, Thuja plicata puts on 75–80cm (around 2½ft) of growth a year. “Good growing conditions” simply means the plants have been well-planted so their roots establish easily, with no shortage of water or nutrients along the way.

What type of soil and sunlight conditions does a Thuja plicata hedge need?

Thuja plicata is easy-going when it comes to soil — it will grow happily in any free-draining soil, including shallow chalk, and only really struggles in waterlogged ground. For light, it’s just as flexible, growing well in full sun through to partial shade.

When is the Best Time to Plant Thuja Plicata?

Thuja plicata hedging plants are available in two forms — container-grown or rootballed — and this determines when you can plant them.

Container-grown plants are grown and sold in pots, with their full root system intact and undisturbed. Because the root systems are fully formed, container-grown Thuja plicata can be planted at any time of year, giving you much more flexibility if you’re not planting during the traditional autumn-to-spring window.

Rootballed plants are grown in open fields and lifted from the ground when they reach the right size for sale. The soil around the roots is kept intact and wrapped — typically in netting and hessian — to protect the root system during transport and planting; this wrapped root and soil mass is what’s known as the “rootball.” Rootballed plants can only be dug up and planted between November and early April, while they are dormant. This is because digging a plant out of the field inevitably means cutting some of its roots, and from April to October the plant is actively growing and needs to take up plenty of water. Cutting roots during this active growing period can kill the plant, as it’s left unable to draw up enough water to support itself.

So, the best time to plant Thuja plicata depends on which type you’re buying: container-grown gives you year-round flexibility, while rootballed plants need to go in the ground between November and early April.

How to Plant a Thuja Plicata Hedge

Good planting technique makes all the difference to how quickly your Thuja plicata hedging plants establish. Take the time to prepare the ground properly and plant with care, and you’ll give your hedge the best possible start.

1. Clear any grass/turf or perennial weeds from the line of planting.
2. Mark the line of planting and positions of the plants.
3. Dig the holes or trench to a suitable size – normally around twice the size of the rootball. If you are planting 60cm apart, it may be easier to dig a trench.
4. Break up the soil in the bottom of the hole to ensure it isn’t compacted.
5. Where the soil is poor, remove some of the soil and mix in good quality screened top soil, John Innes No.3 compost, or Tree & Shrub Planting Compost, blending it with the existing soil rather than replacing it entirely.
6. Mix a controlled-release fertiliser, such as our Greenshutters 12 Month Controlled-Release Feed, into the soil at the recommended rate.
7. Water pot-grown root balls thoroughly before removing the containers.
8. Keep rootballed plants shaded and moist right up until they go in the ground.
9. If conditions are difficult, Rootgrow Mycorrhizal Fungi can help plants establish a strong root system quickly. It needs to make direct contact with the roots, so apply it according to the pack instructions at planting time
10. Carefully remove container-grown plants out of their pots without breaking up the root ball. For rootballed plants, there’s no need to remove the biodegradable wrapping — it’s better left in place.
11. Ensure the plant is at the correct depth. The top of the rootball should be just below (1-2cm or an inch) the level of the soil so the rootball is not sitting proud above the soil surface. Avoid burying the stem too deep.
12. Backfill carefully. Return the soil around the roots.
13. Firm the soil. Press out any large air pockets without compacting the ground excessively.
14. Water thoroughly. Soak the entire planting area as soon as you’ve finished planting.
15. Stake if needed. Large plants in exposed spots may benefit from temporary support — just avoid binding the stems too tightly.
16. Mulch the surface. A layer of organic mulch helps retain moisture, but keep it clear of direct contact with the stems.

Once planted, the most important job is keeping the entire rootball and surrounding soil evenly moist while new roots establish into the surrounding ground — especially through the summer months, when the roots must never be allowed to dry out until the hedge is well established.

When and How Should You Prune a Thuja Plicata Hedge?

Trim your hedge once or twice a year:

Late spring to early summer is the best time for the main trim.

If it needs tidying up again, a second trim in late summer to early autumn works well — just don’t leave it too late, as the hedge needs time to put on some regrowth before winter arrives.

Thuja Plicata vs Leylandii: How Do They Compare?

Thuja plicata and Leylandii (Cupressus × leylandii) look similar, but there are a few useful differences to know:

Growth rate: Thuja plicata grows up to 75-80cm (approx. 2½ft) a year, while Leylandii can put on up to 1m (3’3″) a year.

Trimming: Both should be trimmed at least once a year to stay dense; trimming twice a year is often easier since there’s less material to clear each time.

Forgiveness when cut back: Thuja plicata tolerates light trimming into old wood slightly better than Leylandii. That said, as long as Leylandii is trimmed regularly and you leave 5–10cm (2–4in) of green growth, it stays healthy too.

Soil, light and hardiness: Both grow in similar soil, cope with full sun or partial shade, are very hardy, and are generally left alone by deer.

Varieties of Thuja Plicata Hedging Plants

Seed-grown Thuja plicata

Plants raised from seed are simply known as Thuja plicata. They’re cheaper to produce and often used for forestry, but expect some natural variation in growth rate from plant to plant. Cultivars (improved varieties propagated from cuttings) are generally the better choice for hedging, thanks to more consistent health, growth rate and habit.

Here are some of the cultivars (cultivated varieties) that have been selected for hedging:

Thuja Plicata Excelsa

Thuja plicata ‘Excelsa’ is the best variety for hedging. Having grown Thuja plicata on our nursery since the 1970s, we’ve found Excelsa to be an excellent hedging plant with dark green foliage that, like all Thuja plicata, can bronze in winter. It’s disease-resistant and reliably trouble-free — which is why we now grow exclusively Thuja plicata Excelsa.

Thuja Plicata Atrovirens

Once the most common form of Thuja plicata for hedging, but it has largely been superseded by other varieties due to its susceptibility to Thuja Blight (Didymascella thujina), a fungal infection. It won’t kill the plant, but it does spoil the look of the foliage with small, pale patches marked with black spots.

Thuja Plicata Gelderland

Has curvier, slightly lighter, more olive-green foliage, with some resistance to Thuja Blight — though it can still be affected. For this reason, we no longer grow this variety for hedging.

Thuja Plicata Martin

More upright in habit, with healthy dark green foliage that bronzes slightly in winter. It makes a lovely specimen tree, though Excelsa remains the better choice for hedging.

Thuja Plicata Zebrina

A golden variegated form that grows much more slowly. It can be trained into a good hedge, but it takes many years to establish. It also makes an attractive specimen tree, though it’s harder to source than the green hedging varieties.

The Botany of Thuja Plicata

Thuja plicata is an evergreen conifer native to the north-west Pacific coast of North America. Despite the common name Western Red Cedar, it isn’t a true member of the Cedrus genus — that group includes true cedars like the Blue Atlas Cedar (Cedrus atlantica) and Cedar of Lebanon (Cedrus libani).

Other names you might come across include Western Arborvitae, Giant Arborvitae, Shinglewood, or Giant Cedar — though in the UK, it’s almost always known simply as Western Red Cedar.