Why Councils Are Banning Thuja Hedges - and What Homeowners Can Do

Anyone who turns up at the local council’s planning counter today hoping to put in a tall, opaque hedge along the edge of their plot is increasingly met with a firm no. One species in particular has moved into the crosshairs: thuja, a decades-long default in new-build estates. Councils are now deliberately steering people away from it, citing fire risk, poor environmental credentials and declining, disease-prone stands.

How councils slow down thuja hedges through planning rules

There is no single nationwide law that flatly bans thuja. Instead, local authorities use different levers: their local development plans, zoning and landscape requirements, and the detailed rules that sit behind planning and planting permissions.

These documents can spell out exactly which trees and shrubs are acceptable along roadsides, on plot boundaries or within new housing areas-and which are not. In many places, thuja hedges are now named explicitly on lists of prohibited species, often alongside other uniform conifers.

Anyone who plants a newly prohibited thuja hedge anyway risks committing a regulatory offence, being ordered to remove it, and receiving a fine of up to 1,500 euros.

In day-to-day practice, councils tend to apply the rules in a relatively practical way:

• Checks focus mainly on new builds and newly submitted garden or landscaping plans.
• Older, established hedges are often tolerated until they become diseased or develop gaps.
• Some councils offer grants or free advice to help households switch to more nature-friendly hedging.

If you are unsure, it is worth making a quick phone call before planting-either to the council’s planning department or the parks and green spaces team. Reading the local by-laws and guidance can prevent expensive surprises later.

Why a former garden favourite has become a problem

Ecologically, it can be almost a dead zone

For years, thuja seemed perfect: evergreen, quick to form a dense screen, low-maintenance and inexpensive. From an ecological perspective, however, the result is sobering. Conservation groups now describe it as “green concrete”, and there is a very specific reason behind that label.

Its scale-like leaves contain compounds that, as they rot down, make the soil markedly more acidic. The pH can fall to below 5. Many soil organisms, fungi and bacteria disappear, and earthworms become scarce. In extreme cases, what remains is an almost sterile strip of ground where very little else will grow.

While a mixed hedge can support dozens of animal species, a monotonous conifer hedge provides food or shelter for only a small number of creatures. Specialists cite figures that are hard to ignore:

• up to 35 small-mammal species around diverse hedgerows
• about 8 bat species
• in some cases more than 100 insect species
• up to 80 bird species that rest or nest there

At the same time, populations of many native bird species are falling. In tightly built-up residential areas, every element that offers food and nesting sites matters. A sterile wall of conifers does very little to help.

Fire risk right between homes

Fire safety is at least as significant. Thuja contains essential oils that build up strongly in hot, dry conditions. During prolonged dry spells, a single spark-such as from an outdoor fire pit, a discarded cigarette or an electrical fault-can be enough for the hedge to ignite quite literally.

Tests show: a dried-out thuja hedge can flash over within seconds and reach temperatures well above 800 degrees.

In closely spaced estates, such a hedge can behave like a fuse between garages, carports and houses. Firefighters have been reporting for years on front gardens where one hedge fire has damaged several house façades at once.

There is also the age factor: the big thuja boom dates back to the 1970s and 1980s. Many plants are now old, past their best and affected by fungal diseases such as Coryneum. Dry, brown sections further increase the risk-and make the hedges look unattractive.

What to do if your thuja hedge is affected

If the local rules say no new thuja hedges are permitted, that usually applies only to fresh plantings. It becomes more complicated when an older hedge is badly damaged and needs replacing-or when the council contacts you directly.

In those cases, many authorities recommend switching completely to a “hedge of native shrubs”. It takes a bit more effort to establish, but it pays off over time for soil health, wildlife and lower fire risk.

Removing an old thuja hedge properly

Garden professionals generally advise removing the root stumps mechanically-using a digger, spade or a stump grinder. The soil beneath is often strongly acidified and depleted. It needs a proper recovery period before new planting can succeed.

• Work in around 50 litres of mature compost per linear metre.
• Add a small amount of carbonate lime or similar products to raise the pH.
• Loosen thoroughly and, if possible, leave the ground to rest for a few weeks.

Important: do not simply shred the old clippings and use them as mulch under the new shrubs. The resins and terpenes they contain inhibit germination and suppress soil life.

It is better to dispose of thuja cuttings via the recycling centre, or compost them only in small quantities over the long term, mixed with plenty of nitrogen-rich material such as grass clippings.

Suitable alternatives for a living hedge

Many councils and conservation advisers recommend mixed hedges made up of native shrubs. They add blossom, fruit and seasonal change to the garden-and they give wildlife a genuine buffet.

Commonly suggested mixes include:

• hornbeam as the backbone for quick, dense structure
• dog rose or other wild roses for flowers and hips
• hawthorn or blackthorn as bird-supporting shrubs
• hazel for early flowers and nuts
• alder buckthorn or cornelian cherry as food sources for insects and birds

A minimum of four different woody species along one hedge line is often recommended. That way, the hedge becomes more resilient and robust. Many regions and councils provide subsidies-sometimes up to a few euros per shrub-if native species are planted and documented.

How to combine privacy screening and nature conservation

A frequent objection is: “I need a dense privacy screen, otherwise everyone can see into my garden.” That is achievable without a sterile conifer wall. With a little patience and smart planning, you can have a hedge that is almost as closed after a few years-but far more alive.

A few practical tips:

• Plant in a fan shape: lower shrubs at the front, taller shrubs behind.
• Start with tighter spacing, then remove individual plants later as they develop.
• Avoid cutting it “with a ruler” every year; shape it lightly and thin more firmly every few years.
• Schedule major pruning for the leafless season, roughly November to December.

This approach keeps enough berries and buds available for birds, and the hedge becomes steadily more attractive to wildlife. If you want especially strong screening, combine shrubs with climbers such as clematis or native honeysuckle.

Why the change pays off over time

At first glance, being pushed away from the familiar strip of thuja can feel like an unnecessary imposition. Yet in many gardens, a different picture emerges after a few years: the new hedge becomes a living focal point of the plot. More birds, more butterflies, more flowers-and greater peace of mind during dry spells and heatwaves.

If you need to replace a hedge anyway, or you are building from scratch, it is sensible to take council signals seriously. A diverse hedge of native species is usually straightforward from a legal standpoint, and it is also more resistant to disease, retains more water in the soil and heats up less than a dark conifer wall.

With summers becoming drier and fire risk rising, planting around the home is increasingly a safety issue. Careful planning delivers privacy, a stronger sense of nature and a better garden microclimate-while also helping you avoid conflict with the council and neighbours.