The ten garden nasties that YOU should avoid – and how to get rid of them: Warning to millions as UK grapples with invasive bamboo crisis dubbed ‘Japanese knotweed 2.0’
They will be a feature of countless gardens across the country – sometimes welcome, sometimes not.
But experts have now urged homeowners to be cautious after compiling a list of ten invasive plants to keep an eye on – or even remove – if they are spotted in your garden.
They include the likes of Japanese knotweed, the much-feared plant which has ruined buildings and scuppered housesales for years.
But they also include ivy, the pretty and versatile plant which, if left allowed to infiltrate brickwork and gutters, can cause problems.
Emily Grant, director of operations at UK-based invasive plant specialist Environet, told MailOnline: ‘The majority of the ten species to look out for, excluding ivy and horsetail, are non-native to the UK.
‘When you introduce a non-native species into a new environment, they don’t bring with them all the pests and bugs and bacteria that might eat it and control it. That means these plants have an advantage over native species.
‘What makes a popular plant is what makes it easier to grow. These plants are easier to grow and they become popular.’
Mrs Grant said these plants have their benefits too, with the non-weeds desired by gardeners because they are pretty or versatile.
But she warned: ‘If you have got Japanese knotweed or root bamboo or giant hogweed, you should consider getting rid of them.
‘They have the prospect of the highest harm. Giant hogweed is harmful to pets because of its toxicity, so that one probably should come out immediately.
‘The rest are more nuisance and should be kept an eye on. Ivy and buddleia if you allow them to grow into your gutters they will potentially cause damage, so best to keep an eye on them.’
Here are her ten plants to watch out for.
Japanese knotweed
Japanese knotweed is notorious for its ability to invade property – and for how difficult it is to get ride of once its found
Homeowners have a duty to declare if Japanese knotweed is present on their property before selling it
Perhaps the best known of all the common invasive plants. The biggest problem is it is highly invasive.
Crucially for homeowners, it can affect a property’s saleability or house price due to the fact owners have to declare its presence when coming to sell.
Residents also have a duty to prevent it from spreading into a neighbour’s property risk potential legal action.
It is also very difficult to get rid of.
Bamboo
It poses a legal risk if bamboo encroaches on to neighbouring properties or comes up through the floorboards in a home, and can result in prosecution or thousands of pounds worth of fines
Bamboo’s aggressive growth has earned it a notorious reputation akin to Japanese knotweed, known for its ability to penetrate building structures and wreak havoc on properties
Another highly invasive plant which is still sold at some garden centres.
It can spread further and faster than knotweed, and is prevalent in gardens due to its popularity on renovation television shows.
Roots spread in all directions and new shoots pop up at regular intervals along them as far as 30ft from the parent plant
Buddleia / Butterfly bush
The buddleia has beautiful flowers which are loved by pollinators such as bees. But it can be particularly invasive
The buddleia is a staple of British back gardens, and have the potential to grow almost anywhere
Loved for its nectar-rich flowers which attract pollinators, it can be very invasive, with prolific seed production which outcompetes native plants.
It will grow practically anywhere, while roots grow into walls, guttering and foundations.
It can eventually cause structural damage within a few years.
Giant hogweed
Giant hogweed is commonly found along watercourses such as streams and rivers, with sap that can make skin extremely sensitive to sunlight and cause painful blisters if exposed to the human body
While giant hogweed can damage the enviornment, it does not damage property
A health risk to people and animals because of its extreme toxicity, the sap contains furocoumarin, which makes skin extremely sensitive to sunlight, causing painful blisters that can recur over months or years.
It is often found along watercourses, so the risk is much higher if you have a river or stream running through your property.
It is potentially damaging to the environment by outcompeting native plants, but it doesn’t damage property. It also spreads prolifically by seed.
Horsetail
The horsetail can cause problems by infiltrating drainage pipes, but it is not strong enough to break into building foundations and paving like other invasive species
Emily Grant, director of operations at UK-based invasive plant specialist Environet, said invasive plants have their benefits too, with the non-weeds desired by gardeners because they are pretty or versatile
An ancient, native plant that is becoming increasingly problematic in the UK.
It is very invasive, quickly takes over via its roots and spores on the wind.
Has a root system which spreads quickly and can grow deep into the ground – sometimes up to two metres. It also grows back from small root fragments.
It is strong enough to break paving but not usually building foundations.
It can also infiltrate drainage pipes through cracks and loose joints, causing blockages or flooding, ruins lawns and takes over flower borders and veg gardens.
Montbretia (crocosmia crocosmiiflora)
The montbretia is part of the iris family and is prevalent in the south west of England, with owners advised to get rid of cuttings at landfill
The plant, also known as crocosmia crocosmiiflora, can quickly overrun its surroundings and stifle native species
A hybrid plant in the iris family, it spreads by seed and a bulb-like storage organ known as a corm, especially in sunny spots. It is particularly bad in south west England.
It can quickly overrun a location and outcompete native flora. So homeowners are advised to make sure it doesn’t spread beyond the boundaries of the garden, and to dispose of any cuttings at a registered landfill site.
Ivy
The ivy is a familiar feature of English gardens, with its distinctive shape and colour. It is regarded as more of a nuisance than a problem
Ivy is often favoured by homeowners for its ability to grow rapidly and cling on. But it can cause an issue if it manages to start growing in cracks
Commonly found in English gardens and doesn’t usually pose a problem.
But its ability to self-cling and grow rapidly can make it a nuisance.
It can damage wall surfaces and roofs, penetrating cracks or joints. The roots grow over time, forcing cracks apart. It can also dislodge roof tiles.
Virginia Creeper
Similar to the ivy, the Virginia creeper can get out of control if not scaled back from time to time
A house in Bromley, south London, which is covered in Virginia creeper, which can grow aggressively
Another climbing plant that can get out of control if not kept in check with regular pruning.
It has a very aggressive growth habit and will cover an entire building if it is allowed to.
It can grow onto roofs, into gutters, and cracks in brickwork.
Bindweed
Bindweed, also know as calystegia sepium, smothering garden plants and shrubs
While annoying, bindweed isn’t really capable of damaging property, paths or patios and can be treated using weedkiller
This weed needs to wrap itself around other structures and plants.
It is a common sight in gardens and hedgerows with its distinctive white trumpet-like flowers.
It has a persistent underground root system which can be difficult to remove entirely – and new plants easily regenerate from a fragment.
It is a nuisance but not a menace. It isn’t really capable of damaging property, paths or patios and can be treated using weedkiller. But it is difficult not to kill everything else around it at the same time.
Tree of Heaven (Ailanthus Altissima)
This plant, native to China, can grow up to 6ft in a single year and produces large quantities of seeds
The Tree of Heaven grows in the Tianmen National Forest, but has also been found in the west coast of the US and in London
Native to China, the Tree of Heaven is also causing a problem in the US, especially California.
It is now quite prevalent in London where it was traditionally planted in the city’s various Squares.
It can grow up to 6ft in a year and produces large quantities of seeds.
It grows new trees from roots and grows back rapidly when cut – meaning it is dubbed Tree of Hell.
Its roots produce a compound that kills other plants nearby and can damage drains and pavements.
