How to remove Buddleia
By Jennifer Holmes

How to remove Buddleia

Buddleia removal

Buddleia (Buddleja davidii) (or Buddleja, summer lilac, butterfly-bush, orange eye) is a popular garden plant used across the UK. Out of the 100 or so different species of Buddleia, Buddleja davidii is the most popular, introduced at Kew in 1896. It has become widely naturalised and colonises disturbed ground such as railway lines, quarries, roadsides. and waste ground. We treat a lot of Buddleis on commercial properties as it presents an issue for amenity access, and can completely block alleyways and even railway tracks.

We’ll talk about how to remove Buddleia roots, and even how to remove Buddleia from walls further down but first let’s start with a few Buddleia pictures from some projects we’ve tackled over the years:

Buddleis on railwayBuddleis on commercial propertiesBuddleis on residential properties

How and where does Buddleia grow?

Because Buddleia is a very common plant bought by thousands of homeowners for its large abundance of brightly coloured flowers, we’ll skip Buddleia identification, though if you would like to know more about this species we have it covered on our Target Weeds page. For now we’re going to focus on it’s growth pattern and Buddleia removal. Buddleia is a not a bush, it is in fact a small multi-stemmed tree that is fast growing, and depending on the environment, may grow 0.5m-2m in height annually.

Once buddleia starts to grow, just like Japanese knotweed, the root systems can weaken any materials as they grow through masonry and brickwork. This is an opportunistic species and can establish in both natural and disturbed areas and can grow in a wide range of conditions. It’s dense growth pattern is not only an issue for property owners but it has a significant environmental impact and can prevent the growth and regeneration of native species. It is semi deciduous, so its leaves shed in the autumn are immediately replaced with a set of new, smaller leaves that persist until the following spring. Buddleias have a fibrous root system designed to wind through the nutritious top layer of soil. They do not possess a tap root. The fibrous root system provides some anchorage, but primarily allows the Buddleia to get the most from the nutrients and water of the growing season. Stem cuttings can also regenerate new plants, and these can be dispersed via waterways.

What’s the problem?

DEFRA has estimated that Buddleia control costs the British economy £961,000 pa, largely because it can germinate in crumbling brickwork and cause damage to old buildings. DEFRA is developing a rapid risk assessment (2018), which will assess the associated risks and impacts of the species to the UK, however, Buddleia is not currently listed among the wild invasive non-native plants listed on Schedule 9 of the Wildlife and Countryside Act, which means it is not illegal to buy and grow Buddleia. Herein lies the problem. Whilst it is freely available in garden centres, it will continue to grow outside the designated planting area. How? Because the Buddleia seeds once dispersed, being light and small can travel a distance in the air and will lodge into infrastructures such as cracks in walls or pavements.

Buddleia exploiting wall

removing Buddleia from walls

So Buddleia’s enormous production of seeds (up to several millions per plant) can easily be transported by wind and water, meaning it is often found growing in many unusual habitats, and this includes cracks in buildings several floors high. Removing established plants is therefore a bigger issue than removing Buddleia from the ground via excavation. Buddleia can be treated with herbicide, either sprayed, or injected into the trunk, and this method is most effective on juvenile plants. Treatment should be carried out at the right time of the year, and following a strict methodology. Done correctly, the plant will then whither and die, however will need to be extracted from where it may be lodged in the wall and any damage repaired. This is not a DIY job – it must be carried out by professionals.


Eradication via careful excavation of the above ground and below ground elements of the plant can be achieved by excavation. It is vital that all parts of the plant are removed to be successful otherwise you may see more growth next season, or worse, it could have spread onto neighbouring land. Again, this needs to be done by professionals who are highly trained to spot Buddliea fragments when excavating.


So clearly Buddleia is a lovely looking plant, but it needs to be controlled in order to avoid any of the issues outlined above. Most gardeners will want to control it so it does not take over, so the real problem is for commercial businesses, land owners and property management companies, with Buddleia growing out of control. Our best advice is – catch it early, before it gets taller than you. Young plants will be easier and less costly to treat or remove, and you will be eliminating further problems such as seeds lodging and growing in hard to access or inaccessible locations. Take the picture of Buddleia growing on the sidings of the railway track – that was a big project that involved a lot of management and planning, and could have been avoided if the Buddleia was treated earlier on.

Get in touch if you need help with Buddleia.

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