What is Japanese knotweed

Japanese knotweed is a native perennial plant of Japan. It mainly propagates vegetatively, meaning new plants spread and grow from small pieces of existing plants. It sprouts from rhizomes in the spring months and can grow to a height of 4 meters in the summer and then dies back into dormancy in the late autumn. It is considered one of the top 10 most aggressive, invasive and destructive plants in the world. Its characteristics means it poses a variety of risks for a home owner. Including;

• Small stands of knotweed can quickly spread and infest large areas of land/gardens and there is a real danger of the contamination of neighbouring properties, leaving the land owner at risk of litigation.
• It can cause damage to paths, septic systems, drains, driveways, gardens, outbuildings etc. thus impacting property values.
• Japanese knotweed  is an aggressive coloniser that in many cases out competes native vegetation. Eventually monopolising the area in which it grows. This has impacts on indigenous flora and fauna and can speed up erosion of top soil.

 

How did I get Japanese knotweed in my garden.

Japanese Knotweed does not self-seed. It spreads by small pieces of the plant being transported to other areas and regrowing.

 

How does Japanese knotweed spread.

Japanese Knotweed does not self-seed, it is spread through accidental or deliberate transportation of parts of the plant, stems and rhizomes (roots). Even the tiniest part of a plant can starts a new growth stand of the plant.

Cutting or mowing Japanese knotweed can cause it to spread very quickly over large.it is even transported on muddy shoes, tools and car tyres.

 

How to remove/kill/dispose of Japanese knotweed.

There are various methods to ‘get rid of’ Japanese knotweed, ranging from herbicides, that are used over an extended period, Excavation and removal or burial.

 

How do I know if I have Japanese knotweed

Japanese knotweed is a plant with thick bamboo like stalks, large green leaves and white flowers. However Japanese knotweed changes appearance during different growing stages, and so it is always advisable to get a professional, qualified surveyor to identify any suspect plants.

 

Is Japanese knotweed harmful to humans and animals.

No, it is not harmful to people or animals.

 

What is a Japanese knotweed rhizome.

The rhizome is the part of the plant that spreads underground, a bit like roots. Its outside is brown and if snapped the inside usually had an orange or yellow appearance.

 

What is the cost of removing Japanese knotweed.

The costs vary on different factors, such as, the area, age and size of the infestation and the method of treatment that is needed to reach the desired outcome of the project. This is usually established after a survey by a professional, qualified JKW surveyor.

 

Can I get rid of Japanese knotweed naturally

At this moment there are no natural enemies to help control or kill Japanese knotweed in the UK. The eradication of the plant is usually achieved through the use of an herbicide or through excavation.

 

How to report suspected Japanese Knotweed.

You can report suspected infestations of Japanese knotweed to the environment agency.

 

Can I get a mortgage on a property with Japanese knotweed.

Yes, but many lenders a very cautious of offering finance on infected properties and will require a professional survey and implemented management plan in place before they proceed.

 

How fast does Japanese knotweed grow.

Incredibly Japanese knotweed can grow up to 10cm per day and given favourable growing conditions can reach a height of 4 meters.

The rhizomes (roots) can spread up to 7metres in diameter and reach a depth of 3 meters.

 

What to do if I have Japanese knotweed in my garden

Get Japanese knotweed identified by a qualified surveyor, and then it is your legal responsibility to control or kill it. This is to prevent its spread into neighbouring properties and to protect your own. You are at risk of litigation if it is found that the Japanese knotweed has encroached on to land that is not owned by you.

 

What is a Japanese knotweed insurance backed guarantee.

An insurance backed guarantee will cover further treatment of your Japanese knotweed infestation, if it reoccurs within a stated period, from the point at which the guarantee is supplied. Usually 10 years.

 

Can I treat Japanese knotweed myself.

The actual treatment, by herbicides, of Japanese knotweed is not difficult, as long as you have good knowledge of the plants biology and growing cycle. However, it must be noted that mortgage lenders do not recognise home treatment plans. They require a professional, accredited insurance backed management plan, before they will proceed with an application.

 

Can Japanese knotweed damage my house.

If you have a structurally sound house, with substantial foundations then no, the chances of knotweed damaging your house are small. However, if Japanese knotweed is present on your property, you should put a plan in place to control or eradicate it.