Look out! Bamboo is the new Japanese Knotweed
Bamboo, a favourite screening plant among landscape gardeners, is causing havoc in the housing market, as an invasive threat to the homes and buildings.
Bamboo has joined Japanese Knotweed in the ‘Little Shop of Horrors’ of invasive plants, causing damage to property and estate agents’ business, according to specialist property insurer, CLSQ.
“It’s the running bamboo that can cause significant destruction to a property as the root system can reach metres in distance and in various directions,” says Lorenzo Tejada Orrell, Chief Innovation Officer at CLSQ.

“Cases have shown shoots of bamboo creeping through skirting boards, out of the chimney breast, through floorboards and even through a homeowner’s oven! Bamboo shoots are so strong that they can penetrate through concrete, tarmac and cavity walls.”
Until now, Japanese Knotweed has been the high profile villain in the garden, causing untold damage to properties and to otherwise safe property transactions, causing fall-throughs, lost revenue and broken chains.

To indemnify agains the risks, CLSQ has launched an insurance product – Bamboo Indemnity Insurance – specifically targeting bamboo intrusion into neighbouring properties. to insure against market value loss, the problem is so potentially great.
The product offers protection against financial loss for a period of five years. Where a survey has been undertaken to show no bamboo on the property or neighbouring, the policy will cover both the purchaser and the lender. If no survey has been undertaken the policy will cover just the lender.
Meanwhile, surveyor Stokemont has listed the most destructive garden plants, to property in a ranked guide to the leading offenders.
The added value to a property of a well-stocked garden could be severely undermined if there are ‘dangerous plants’ amongst the greenery, says property surveyor Bradley Mackenzie of Stokemont.
Five dangerous plants that could wreck an instruction
Japanese Knotweed – removal difficulty: High
Japanese knotweed is an invasive plant with bamboo-like red shoots and shovel-shaped leaves. It can grow up to 3 metres tall in spring and summer. However, the worst part about this plant is that its roots can reach down to 20 metres underground.
According to Stokemont, the spread of Japanese knotweed underground could destroy pipework and drains and weaken building foundation or paving, leading to foundational collapse and poor flood defences. Due to these damages, Japanese Knotweed is listed as a defect to the property by RICS Homebuyer Reports, with the potential to reduce the price of your property by anywhere between 5% and 20%!
With searches for ‘getting rid of Japanese Knotweed’ up by over 5,000% in the last month, Bradley Mackenzie from Stokemont recommends:
“If you spot Japanese knotweed in your garden it is really important to take immediate action before it’s too late. We would highly recommend you seek professional help when removing them as they re-establish easily from even the smallest remains. If you prefer doing it yourself, a strong herbicide such as Glyphosate would be the most effective method to kill those zombie-like plants!”
Giant Hogweed – removal difficulty: High
Giant Hogweed is similar to Japanese Knotweed in its invasive nature and ability to spread rapidly. More easily spotted in June and July, this cow-parsley-like plant has thick green stems with purple spots and white flowers shaped like a round umbrella on top.
Bradley comments: “Giant hogweed is widespread across the UK, especially around rivers and ponds. Its sap is phototoxic and can cause severe skin burns or scars under sunlight. Though it’s unlikely to cause direct harm to your property, buyers may still refuse to pay a higher price if this weed is present because of its high cost of removal – up to £15,000.”
Buddleia (Butterfly bush) – removal difficulty: Medium
Buddleia, also known as butterfly bush, has large, drooping spikes of densely clustered, small, purple (or sometimes white) flowers. It has long, narrow leaves and the flowers have ahoney-like fragrance.
Once buddleia begins to grow, its roots can damage materials as they can grow through masonry and brickwork, meaning this plant has the potential to cause costly repairs, or in particularly bad cases, may cause a property to become unsafe or unstable. DEFRA has estimated that Buddleia control costs the British economy £961,000 per annum, because of its ability to germinate in crumbling brickwork.
In light of its somewhat tricky removal, Bradley has suggested: “Buddleia can be treated with herbicide, either sprayed, or injected into the trunk. If carried out correctly, the plant will then die, however it will need to be extracted from where it may be lodged in the wall. It is therefore recommended that you consult a professional, rather than trying to remove it yourself.”
Himalayan Balsam – removal difficulty: Low
Himalayan Balsam is from the Himalayas and was brought to the UK in 1839. It grows up to 2 – 3 metres tall and has pink flowers in summer and early autumn. Despite its beautiful colours, this invasive plant could spread 800 seeds metres away or even through rivers, potentially killing off other plants and reducing biodiversity by stealing all lights, nutrients or water.
While this non-native plant is not poisonous to humans, Bradley MacKenzie suggests that it may cause other issues for homeowners: “Himalayan Balsam is quickly becoming a more common sight in the UK. It is illegal to plant in the wild due to its significant ecological impact and potential buyers may be wary. It is recommended to keep this plant controlled or get rid of it all together, and make sure it does not spread to your neighbours’ home as it can be illegal! ”
Rhododendron Ponticum – removal difficulty: Medium
Rhododendron Ponticum is a vigorous and invasive weed species of rhododendron, which often blooms in spring. It produces branching, woody stems, and spreads almost as wide as it grows high, the woody stems eventually forming tree-like trunks. Mature height is around 6-8m and the overall spread in the region of 6m.
Rhododendron Ponticum is listed under Schedule 9 of the Wildlife and Countryside Act 1981, making it illegal to plant in the wild, as well as illegal to allow it to spread from your property.
When removing Rhododendron Ponticum, any prunings or waste material must be disposed of responsibly. Rhododendron Ponticum contains toxins that are harmful to people and livestock. Take care when handling cut foliage, or when transporting for disposal.
Bradley advises: “There are several methods which you can attempt to use to remove this plant, such as hand pulling or stump treatment, however, these methods depend on the size of the infestation and it might be difficult to know which one will be the most effective. Therefore, it is best to talk to professionals.”
Main pic courtesy of Environet UK
Told you so in 2023 – comments 😀
https://thenegotiator.co.uk/news/landmark-case-signals-new-wave-of-japanese-knotweed-litigation/