Invasive Weeds

There are a number of Invasive weeds within the UK.

These range from the well documented Japanese Knotweed to the lesser known Ragwort.

IWM’s 3 year control and management system can treat and eradicate Giant hogweed.
Our fully qualified technicians will conduct a site survey and develop a bespoke treatment programme to ensure customer satisfaction.
IWM are also qualified to treat and destroy other invasive plant life such as Himalayan Balsam and Ragwort. Please ask us for details and to arrange a site survey. All site survey fees will be 100% refunded if IWM are asked to complete the treatment programme.


Himalayan Balsam Removal Control (IWM)
Himalayan Balsam Removal (IWM)

Himalayan balsam (Impatiens glandulifera) is a relative of the busy Lizzie, but reaches well over head height, and is a major weed problem, especially on riverbanks and waste land, but can also invade gardens. It grows rapidly and spreads quickly, smothering
other vegetation as it goes.




Horsetail Removal (IWM)

Horsetail Equisetum arvense (often incorrectly called marestail) is a deep rooted invasive plant that can cause havoc to driveways, car parks & gardens. It speads via an underground rhizome system and like many invasive species is no respecter of borders! It is a persistent pernicious plant that needs several applications of a professional grade herbicide to ensure its complete eradication. As the image shows it develops fir like green shoots up to 60cm tall




Ragwort Removal Control (IWM)
Ragwort Removal Control (IWM)

Ragwort (Senecio jacobaea) is not usually a significant problem in gardens, but its poisonous qualities can make it a serious weed of paddocks and gardens backing onto fields grazed by horses or cattle.




Hogweed Removal Control (IWM)
Hogweed Removal Control (IWM)

Giant Hogweed Heracleum mantegazzianum is harmful not only to the environment but can cause severe blistering when it comes into contact with human skin and can leave the victim
with permanent scarring.

Giant Hogweed is a highly invasive plant species that will cover large areas of land if left untreated. Each individual flower head can produce up to 1500 seeds, causing soil erosion especially on riverbanks and as a result can be found in large quantities at roadside and riverbanks.


Buddleia Removal Invasive weed Removal
Buddleia Removal

Buddleia davidii (spelling variant Buddleja davidii), also called summer lilac, butterfly-bush, or orange eye, is a species of flowering plant in the family Scrophulariaceae, native to Sichuan and Hubei provinces in central China, and also Japan.

buddleia davidii otherwise known as Butterfly bush is another invasive species that was introduced in the UK in the 19th Century to attract insects.

However, if this species is neglected for a period of time it will spread rapidly over walls and onto adjoining land including development projects and derelict land.

Buddleia is quickly becoming a major problem across England and Scotland and treatment programmes are highly advisable .


Rhododendron Removal
Rhododendron Removal

Rhododendron invades areas both vegetatively and via seed. Established plants spread by lateral horizontal growth of the branches. A single plant may eventually end up covering many metres of ground with thickly interlaced, impenetrable branches. Where the horizontal branches touch the ground, they will root, continually extending the area of Rhododendron cover.

Rhododendron is capable of extending into areas which it would otherwise be expected to fail. For example it has been known to dominate wet land with its extensive canopy while the roots remain on dry land.


Potentially toxic chemicals, particularly ‘free’ phenols, and diterpenes, occur in significant quantities in the tissues of plants of Rhododendron species. Diterpenes, known as grayanotoxins, occur in the leaves, flowers and nectar of Rhododendrons. These differ from species to species. Not all species produce them, although Rhododendron ponticum does.

These toxins make Rhododendron unpalatable to most herbivores. Phenols are most concentrated in the young tissues, such as young emergent leaves and buds. This provides a primary defense against herbivores, before the tissues have acquired the added deterrent of physical toughness found in older tissues. Young emergent leaf buds have the additional protection of a sticky exudate which also contains phenols. This physically discourages small invertebrates from eating the buds, because they get stuck in the exudate. Its poisonous nature must act as a further discouragement.

Grazing animals are discouraged from eating Rhododendron foliage because of its toughness and unpalatability. The unpalatability is learned and cases of poisoning may result in animals such as sheep and cattle if they ingest sufficient quantities because of extreme hunger or inexperience. The general toxicity of Rhododendron to herbivores means that it cannot generally be controlled by grazing.

Cases of human poisoning are also known. Most are caused by the consumption of honey produced from Rhododendron flowers. This is known as ‘Mad Honey Disease’, or ‘Honey Intoxication’. Cases of this have been recorded from as far back as 400 BC. It results in relatively short-lived intestinal and cardiac problems and is rarely fatal. The severity of symptoms depends on the amount of contaminated honey consumed. It is worth thinking carefully about the siting of bee hives if Rhododendron is a prominent feature of the area.

It is a threat to native species of animal and local fauna. IWM have carried programmes of treatment and eradication for the forestry commission as well as private contractors.


Devils Helmet / Wolfsbane
Devils Helmet / Wolfsbane

Aconitum, otherwise known as wolfsbane, Devils helmet, Monkshood, blue rocket to name but a few, is a highly poisonous perennial plant found across the UK. The name derives from the Greek translated as “without struggle” The plant produces toxins which can affect the body and in many cases over the centuries has resulted in death

The plant has recently been in the national news when a gardener sadly passed away after contact with Aconitum.

The roots are extremely poisonous if ingested and there have been small cases of death resulting from contact with the plant. Please contact IWM for an eradication programme for this deadly species.

IWM Promise

As more and more Invasive Weeds and foreign species of plant are been found every year IWM guarantee we will be at the forefront in their control and removal.