The cost to remove japanese knotweed depends on several factors, such as site conditions and the extent of the infestation. In general, larger sites require more extensive excavation and removal than smaller sites. The treatment method also impacts costs. Chemical treatments can be more expensive than non-chemical approaches, but they are also safer for people and the environment.

Japanese knotweed can be a serious problem, affecting garden growth, damaging driveways, drains and patios and potentially causing structural damage to buildings. It can also affect resale value. Mortgage lenders and insurers may not accept properties where it is present, and buyers of a property with Japanese knotweed may be required to have a management plan in place before buying the home.

Understanding the Cost to Remove Japanese Knotweed: What Factors Affect Pricing

Herbicide treatment is the cheapest option for removing Japanese knotweed, but it can take several years to complete and limits how you use your land afterwards (e.g. you cannot build on it). It’s also worth bearing in mind that chemical treatment can cause environmental damage, with glyphosate (the active ingredient in Roundup) causing harm to wildlife and the gut bacteria of pollinating bees.

Excavation and removal is a more reliable approach, but it can be costly. This involves digging out and removing the invasive weed, usually to a depth of two metres. The waste is then removed as ‘controlled waste’ and taken to a licensed landfill site. This process must be carried out by a qualified PCA registered surveyor, who can provide a five-year plan and insurance-backed guarantee.