Japanese Knotweed Case Study – Southampton & Portsmouth

Japanese Knotweed Case Study – Southampton & Portsmouth

Multi‑Site Eradication Across 16 Residential, Commercial & Public Open Space Locations

IVM was appointed by a major housing association to eradicate Japanese Knotweed across 16 sites in Southampton and Portsmouth. These locations included residential gardens, commercial premises, car parks and wooded public open spaces, each requiring tailored treatment methods to ensure full compliance and long‑term eradication.

Project Overview

Location: Southampton & Portsmouth
Site Type: Residential, commercial and public open spaces
Contamination: Japanese Knotweed across 16 separate sites
Treatment Methods: FAST System, stem injection, knapsack application
Programme: Three‑year treatment plan with ongoing monitoring

The Challenge

The housing association required a coordinated eradication programme across a wide range of site types, each with different access constraints and environmental considerations. Treatments needed to be delivered safely and consistently throughout the growing season, with clear reporting and progress tracking across all 16 locations.

Our Solution

IVM implemented a structured three‑year treatment programme using the FAST System alongside stem injection and knapsack application depending on site conditions. Monthly Site Progress Reports were issued to the client, and regular monitoring visits were carried out following the completion of treatment. No re‑growth of Japanese Knotweed has been recorded on any of the sites.

Outcome

• Successful eradication across all 16 sites
• FAST System, stem injection and knapsack methods applied as required
• Monthly progress reporting throughout the programme
• Long‑term monitoring with zero re‑growth recorded
• Full compliance for residential, commercial and public open space environments