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Herbicide treatment for Japanese knotweed
Herbicide treatment is a popular and cost-effective method of controlling Japanese knotweed where the ground will not be disturbed. It is widely used in residential gardens, boundary areas and open spaces where long-term control is acceptable and immediate excavation is unnecessary.
Herbicide treatment does not provide rapid removal, nor is it suitable where construction, landscaping or ground disturbance is planned. In these cases, excavation-based solutions such as excavation or Resi-Dig-Out™ are more appropriate.
When herbicide treatment is used
Herbicide treatment is typically chosen where:
- the ground will remain undisturbed
- a lower-cost long-term solution is preferred
- access is limited and excavation is impractical
- the site can be monitored over several seasons
- the infestation is not affecting planned building works
It is widely used in:
- residential gardens
- boundary and fence lines
- public open spaces
- commercial sites with no planned disturbance
Where a faster or more certain outcome is required, DART™ or Resi-Dig-Out™ may be more suitable.
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How herbicide treatment works
Herbicide programmes are delivered across multiple growing seasons and typically include:
- four herbicide applications over two growing seasons
- annual monitoring visits in years three and four
- additional treatment for large or mature stands
Our applications are safe for pets once the herbicide has dried. For reassurance, we recommend waiting 90 minutes before allowing animals into treated areas.
An insurance-backed guarantee underwritten by an AA- rated insurer can be issued to cover any regrowth.
Glyphosate use in knotweed treatment
Glyphosate is the active ingredient used in our herbicide programmes. It has been used in the UK since 1976 across sectors such as farming, forestry and amenity management.
Regulators including the European Chemicals Agency (ECHA) have concluded that glyphosate poses little to no risk when used correctly. It has been assessed extensively by regulatory bodies in the EU, USA and the World Health Organisation.
All treatments are carried out by qualified technicians with NPTC Level 2 (PA1 and PA6) certification.
Application techniques
We use the most appropriate application method for each site:
Foliar application
A targeted spray applied to the plant’s foliage. Suitable for most residential and open sites.
Stem injection
Herbicide is injected directly into mature stems using a specialised injector. This method avoids spray drift and is recommended near:
- watercourses
- protected trees
- hedges or sensitive plants
- confined spaces
Small or immature plants cannot be treated with injection, and some evidence suggests it may induce rhizome dormancy. It should be considered a control method rather than a guaranteed eradication technique.
Spot treatment
Precise application used for small regrowth or sensitive areas.
Limitations of herbicide treatment
Herbicide treatment:
- cannot guarantee complete removal of viable rhizome
- is unsuitable where ground disturbance is planned
- requires multiple treatment seasons
- is not accepted for development sites requiring definitive clearance
- may be restricted near watercourses or sensitive habitats
For gardens where future works are planned, excavation methods such as Resi-Dig-Out™ are strongly recommended.
Professional vs DIY herbicide treatment
Although glyphosate weedkillers (e.g. Roundup, Weedol) are widely available, DIY attempts often fail due to:
- incorrect timing
- incorrect dosage
- limited access to professional-grade formulations
- misjudging the plant’s growth cycle
- extensive underground rhizome systems
Professional treatment provides:
- stronger formulations
- structured multi-year programmes
- stem injection where needed
- monitoring and retreatment
- insurance-backed protection
For reliable long-term control, professional treatment is strongly advised.
Case Studies
Former Airfield, Essex
Herbicide, Swansea
Herbicide, Stanmore
Links to related services
Accreditations
We have robust systems in place for Environmental and Health & Safety management. Risk assessments are carried out for every aspect of our business to identify situations where harm could be caused. We have an ethos of continuous improvement to eliminate or reduce the risks with detailed working procedures, on-going training and monitoring.
All our staff have health and safety and emergency first aid training. We are also accredited by CHAS and Constructionline and are members of the Property Care Association (PCA).
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