“The Terrorist Weed” – Japanese Knotweed Eats Houses!

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Guest post by Rob McColl, a property investor and fellow blogger from RentalRefurb

 

Rob's story:

I was recently refused a remortgage on a rental property of mine due to the presence of Japanese Knotweed in the garden, spreading onto my land from railway lines at the rear. This is what I discovered in the panic stricken weekend which followed:

A Brief History

Japanese knotweed ( Fallopia Japonica) evolved in the volcanic rock of Japan, and developed an extremely hardy root system to overcome the regular deposits of ash and generally hard environment. The roots forced their way deep into the stone to enable its survival.

This wasn’t so much of a problem in England in the 1850s, when Japanese Knotweed was shipped to Kew Gardens, cultivated, and then sold commercially!

Were They Mad?

Japanese knotweed was introduced as a pretty, ornamental plant, which grew well and could stabilise loose soil banks in mining areas and railway embankments.

It spread unnoticed using water courses, and from cuttings being disposed of. The large scale movement of soil for roadworks also aided the expansion.

Why Is Japanese Knotweed A Problem?

• Japanese Knotweed can grow at a massive 20cm a DAY!
• It exploits cracks in concrete and tarmac  with roots and stems.
• There are no seeds produced in the UK- but the plant can regrow from just 0.8g of the root and underground rhizome.
• The presence of Japanese knotweed can knock thousands off the value of your property.

Check out this video showing how fast it grows

What Does It Look Like?

DEFRA describe Japanese Knotweed as

..begins to grow in early spring and can grow in any type of soil, no matter how poor. It can grow as much as 20 centimetres per day, and can reach a height of 1.5 metres by May and 3 metres by June. It does not produce viable seeds in the UK, but instead spreads through rhizome (underground root-like stem) fragments and cut stems. Japanese knotweed:

• produces fleshy red tinged shoots when it first breaks through the ground
• has large, heart or spade-shaped green leaves
• has leaves arranged in a zig-zag pattern along the stem
• has a hollow stem, like bamboo
• can form dense clumps that can be several metres deep
  produces clusters of cream flowers towards the end of July
• dies back between September and November, leaving brown stems

The fleshy shoots are often described as looking like red asparagus spears. The stems are similar to a bamboo, and often ‘snap’ with a similar sound to a carrot.

What Can I Do About It?

Japanese knotweed can be treated in a few  ways-:

• Spraying can take a few years to eradicate, and will require several treatments with chemicals. This is often best for smaller infestations and sites with difficult access.
• Physically digging out the plant an entire rhizome system is a faster way to deal with a japanese knotweed infestation, and may be suitable for larger or commercial sites.
• Burial. The contaminated soil is buried within a root barrier system deep underground. This isn’t considered eradication.
• Bugs!A Japanese bug, aphalara itadori, which feasts almost exclusively on knotweed was released in the uk in 2010.
• Eat it! Yes its edible. See here for recipe!

The RICS information paper is an excellent source, particularly if you need to show a lender or tenant that the issue isn’t ‘dangerous”

You Must Not:

• allow invasive plants to spread onto adjacent land – the owner of that land could take legal action against you
• plant or encourage the spread of invasive plants outside of your property – this can include moving contaminated soil from one place to another or incorrectly handling and transporting contaminated material and plant cuttings
• japanese knotweed is classified as controlled waste under the Environmental Protection Act 1990.

So What Happened To Me?

After that initial furious googling of japanese knotweed, and reading horror stories, I spoke to Environet, who reassured me that the problem was solvable.

I initially tried to contact the owner of the land which had allowed the infestation to cross the boundary, and arranged a meeting with them. They never showed up, and to date have not returned any communication from me.

The lender released funds within a few days of a knotweed survey and the first chemical treatment having being carried out.

In time Environet  put me in touch with a specialist solicitor who is chasing the land owner for the cost of the treatment.

Have you any stories of Knotweed infestation and how it affected you?

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The Property Voice insight:

There are a number of scary stories out there in property-land but this has to be one is one of the scariest. Japanese Knotweed is just so difficult to get rid of once it appears. Nobody will buy your property if they know you have it...aside from a savvy investor at a big discount perhaps and if you hide it you could be in big trouble too!

To get more insight take a quick peak at this five minute clip from BBC's The One Show

Rob talks us through the main points of how to treat and eradicate it, as does The One Show's reporter. But if you want my advice, prevention is better than cure and for me that means trying to avoid inheriting the problem in the first place by checking for signs it exists before purchase. That said, I am aware of a few investors that have taken on such a challenge...Rob seems to be one, albeit reluctantly I imagine.

Like all property problems however, there can be money to be made by getting rid of an existing problem but this one should not be taken on lightly, as the risks are there to see: mortgage withheld, limited sales market, down-valuation and a blighted property to name but some.

I do hope that 'The Terrorist Weed' doesn't strike one of your valued investments! Thanks Rob for the detailed and very practical post here. If you have a story to share on The Property Voice then just get in touch and start a conversation.