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What Plants Are Illegal To Grow In UK

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  • 12-07-2023
What Plants Are Illegal To Grow In UK

This article asks: How do I report invasive plants in the UK? Our guide provides step-by-step instructions on reporting invasive plant species to the appropriate authorities. Discover the importance of early detection and swift reporting in preserving native ecosystems.

Plants To Remove From Your Garden

One of the nine plants that results in a large punishment is spear thistle according to experts. Although it's allowed to cultivate these plants in your garden, it's crucial that homeowners keep them under control.

Invasive plants, like Japanese knotweed, have a stem that spreads quickly. It's known to attack stone fractures and grow through them. This harms building structures if left unchecked. In the meantime, the toxin found in common ragwort may harm the livers of horses and other animals.

UK Law And Invasive Plants

The Wildlife and Countryside Act listed these species in Schedule 9. In recognition of the need to combat invasive plants that pose a threat to the UK. Only Japanese knotweed and gigantic hogweed were initially mentioned. But 36 more invasive species were later included.

And a further amendment prohibited the sale of five of the worst invasive water plants in the UK. Planting or encouraging the growth of invasive plants is illegal and punishable by a fine. Or two years in jail.

How Do I Report Invasive Plants In The UK

Invasive Plants You Can’t Grow in the UK:

 Spear Thistle

In the UK, spear thistles are considered noxious weeds, and it is now against the law to let them grow in your yard. The plant may grow swiftly and injure crops and other vegetation. It has spiky leaves and purple blooms.

 Broad-Leaved Dock

The broad-leaved dock affects crops and plants similar to the spar thistle. It is not weather-sensitive, thus it may readily spread throughout the UK. The plant's wide leaves and spikes of tiny yellow blooms make it easy to identify. 

Common Ragwort - Invasive Plants You Can’t Grow in the UK

 Common Ragwort

Every county in the UK is home to the plant known as common ragwort, which grows in pastures and waste areas. Sand dunes are its natural habitat. Although it also thrives on light, low-fertility soils and overgrazed grassland.

All portions of the plant contain toxic alkaloids, which result in cattle losses due to liver disease. The Ragwort Control Act and the Weeds Act both make reference to it. Deep-rooted ragwort can recover from its roots if they are not entirely removed. However, seeds are mostly to blame for the invasion of uncontaminated grassland.

The wind may carry disc floret seeds up to 72.5 metres. But when it's moist, the seed heads don't open and the seeds don't fall out. Water can also spread the seeds of ragwort. The seeds first float, sink, and then refloat as they start to germinate.

The seeds of common ragwort have been found in crop seeds as contaminants and can be spread through hay. Although the seeds can be eaten by birds, live seeds are seldom discovered in bird droppings. Sheep consume seeds, and they pass through their digestive systems unharmed.

 Rhododendron Ponticum

Since its arrival, Rhododendron Ponticum has spread beyond gardens. Destroying woods and meadows throughout the British Isles. The shrubs choke other plants and trees and block sunlight from reaching plants.

Additionally, certain animals are poisoned by them. The plant also harbours illnesses that can wipe out our native tree species. In the UK, it is against the law to plant it or let it grow.

 Himalayan Balsam

Another unruly plant is Himalayan balsam (Impatiens Glandulifera). Unlike Busy Lizzie, it grows higher than the head. The weed is a serious issue on riverbanks and unoccupied land.

Additionally, it can be a nuisance in gardens and allotments. It outgrows and smothers other plants with its rapid growth. Seeds are distributed by wind, water, and human activity. Himalayan balsam cannot be introduced to the wild or planted.

 American Skunk Cabbage

Due to its escape from gardens and into the wild, this plant can cause several issues. Large, leathery leaves and brilliant yellow blooms are features of this plant. Its seeds are dispersed through streams and most likely by animals as well.

The enormous leaves of this plant shade and outcompetes other native species when they grow in thick clumps in the wild. This harms riparian environments. And once it has a presence in a place, it may expand widely very rapidly. In the UK, it is prohibited from sale.

American Skunk Cabbage - Invasive Plants You Can’t Grow in the UK

 Curly Waterweed

Commonly offered for sale for garden ponds was curly waterweed. But this is yet another invasive water plant that has been added to the list of invasive species.

To establish this plant or encourage its growth in the wild is against the law. This plant is another aquatic non-native harming British rivers that have expanded in the wild.

 New Zealand Pigmy Weed

The New Zealand Pigmy weed is a menace to everything around it. It's known for destroying other plants that you might be attempting to grow in your garden.

The selling of this seed has been prohibited since it is an invasive plant. The plant may affect even aquatic habitats. It has tiny green leaves and clusters of tiny white blooms.

Japanese Knotweed - Invasive Plants You Can’t Grow in the UK

 Japanese Knotweed

This invasive, non-native perennial poses a serious threat. It spreads through underground rhizomes, growing fast and clumping. It can regenerate from even the smallest pieces of rhizome, however, in the UK, it seldom produces seed. Because of this, it can spread and take over a region. Outcompeting local vegetation and harming ecosystems.

Despite originally being ornamental, it is now under strict regulation. Encouraging Japanese knotweed to flourish in the wild is illegal. If you are selling your home, you need to inspect the garden and note the presence of Japanese knotweed. It's not against the law to have it in your garden. But you risk legal action if you don't try to control it, let it spread, or don't properly get rid of it. It is preferable to contact a specialist because it's quite tough to eliminate this plant on your own.


Garden ponds may support the growth of water ferns, another aquatic plant that is forbidden. This might have a significant impact on aquatic vegetation and wildlife. It is a severely invasive species, especially in streams.

 Parrot’s Feather

Another aquatic plant that is prohibited is Parrot's Feather. It is a well-liked pond plant that produces mats of feathery-looking leaves. It smothers freshwater and streams in the wild by spreading roots from fragments.

 Floating Pennywort

This aquatic plant was first introduced to garden ponds. But it has now spread to the wild and is having negative ecological effects. It produces dense mats of rounded leaves that blanket the surface of rivers.

This restricts light for photosynthesis and lowers oxygen levels. It affects numerous aquatic animal species and outcompetes many native flora. 

 Floating Pennywort - Invasive Plants You Can’t Grow in the UK

 Curled Dock

Curly leaves and spikes of tiny yellow flowers are features of curled dock. Another hazardous plant. It is a weed that is adaptable and can spread swiftly.

 Swamp Stonecrop

Our streams' ecosystem is harmed by Australian swamp stonecrop and Pygmy weed. It's forbidden in the UK. It can grow from a single small stem piece and suffocates other aquatic life.

Elodea Nuttallii - Invasive Plants You Can’t Grow in the UK

 Elodea Nuttallii

It is prohibited to establish or encourage the growth of this common garden pond plant in the wild. This is another oxygen-producing pond plant that spreads swiftly. It can also outcompete native species. This harms biodiversity in British rivers when it escapes into the wild.

 Giant Hogweed

Giant hogweed, which resembles cow parsley, can reach heights of 10 feet. Chemicals in the plant's sap can burn and blister people when they get sunlight on their skin. It spreads by seed and can outcompete other plants.

This poses a significant threat near rivers. And a threat in locations where people live. In the UK, it is against the law to plant this or for it to grow naturally.

 Gunnera Tinctoria

The common garden plant known as Chilean Rhubarb is Gunnera Tinctoria. It is cultivated next to ponds or in moist locations. Though it is praised for its exotic appearance and enormous leaves.

However, it is illegal to cultivate this plant in the wild in the UK. It has the power to propagate, change natural ecosystems and outcompete many other species.

Do you have an invasive plants problem? If you require invasive weed removal in Essex, London or throughout the UK, contact our expert today.