Japanese Knotweed Survey
Japanese Knotweed Photo


Japanese Knotweed Survey

>contact us > terms & conditions
>home > sample report

Removal by dig and dump (pdf file)

Sample report for removal by dig and dump


Japanese knotweed mechanical control  

tel: 0333 456 7070
mob: 07950 259 905


Japanese knotweed (Fallopia japonica) is an introduced weed, which has rapidly colonized river banks and areas of waste land. It is a perennial plant, which grows from rhizomes in the spring to a height of about 3m in midsummer with stiff, bamboo-like stems. In the autumn, the leaves and stems die but remain stiff and erect. The plant produces large masses of white flowers in summer but it is not thought to produce viable seeds. The plant over winters in the form of rhizomes, which grow rapidly and have been known to grow through cracks in rock, concrete and tarmac. Cut or broken stems lying on damp soil can root and form new plants. The spread of this plant to new sites may be caused by the transportation of contaminated topsoil because fragments of rhizome as small as 1 gram can produce new plants.

Spread along riverbanks may also occur when the shoots are cut and allowed to float downstream and are washed onto damp soil beside the river. Japanese knotweed forms dense stands, which severely impede access to riverbanks and shade out native species leaving the banks bare and liable to erosion in winter. The rhizomes can penetrate damage and displace stone and concrete embankments and structures.

Mechanical Control

Do not flail mow Japanese knotweed. Cutting should be with simple blades to create a clean cut with no fragments. Cutting the shoots in spring or summer has no long-term control and may encourage the spread of this weed unless the shoots are collected and burnt; the rhizomes appear to be able to survive for many years, even if shoots are cut regularly. Digging, ploughing and dredging are unlikely to have any long-term benefit because of the extensive nature of the rhizome system and because of the ability of even small fragments to re-grow. Transport of soil contaminated with this plant should be avoided and green shoots should not be cut and allowed to float away from any infected area where engineering works are being undertaken but should be collected, dried and burnt. Sieving or screening of excavated topsoil on site through a 1-2 cm mesh may alleviate the problem of contaminated spoil, and will allow re-use of the excavated soil on site.

Failure to manage Japanese knotweed on a development site may result in eventual structural damage. The plant can easily take advantage of cracks within walls or concrete foundations and is able to grow through tarmac surfaces. Japanese knotweed should not be stockpiled within 10 metres of a watercourse. Any movement of contaminated soil and Japanese knotweed for treatment within the site boundary, within a designated area, could involve the treatment of waste and may require a waste management license.

Cutting will not eradicate Japanese knotweed growth and it should be seen as short-term management. It is most effective when used in conjunction with herbicide treatment. Cutting could increase the risk of spread. Pulled stems often have the highly invasive crown material attached to them and must be disposed of in the same way as rhizome. Cut stems are less of a risk, and are safe once they have dried out and turned brown. Stems should be cut cleanly so that they don’t create pieces of stem that may spread and regenerate, in addition they should be left where they can dry out fully. If you intend to treat re-growth with herbicide, you should remove cut material from the treatment area to allow the spray to effectively cover the new growth.

Japanese knotweed can regenerate from just a small piece of stem and drying canes should be left on an appropriate membrane surface, not on soil or grass. Once the stems have dried to a deep brown colour they are dead. This is not the case with crown or rhizome material.

View a sample report for removal by dig and dump (pdf file)

> Identification Service

Not sure if it is Japanese knotweed? Email photographs for our surveyor's expert opinion.

We can also send a surveyor's letter identifying the plant in the photographs if required.
*fees and conditions apply

more info >>

> Japanese knotweed survey

Approval has been given for an insect to be released to control the invasive Japanese knotweed in the North East.

The rampant plant, which was introdu ...

> Japanese knotweed survey

A homeowner who tried to remortgage his £400,000 property had his application refused because of Japanese knotweed in his garden.

Dave Williams, 42, w ...

> A formidable problem

You should aim to completely eradicate the knotweed before any construction works commence, unless you want to incur delays and major expense at a later stage ...


Company’s Registered Office Address: 597 Etruria Rd, Basford, Stoke On Trent, Staffordshire. ST4 6HP.
Japanese Knotweed Survey © Copyright 2011

Japanese knotweed survey, management, control, eradication & land remediation relief.
Areas include Staffordshire, Cheshire, West Midlands, Manchester, Birmingham & Stoke On Trent.

Hosted by Square-Sun Web DesignSquare-Sun Web Design logo