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How Much Does Japanese Knotweed Removal Cost?
If knotweed has turned up in your garden or been flagged on a survey, the first question is what it will cost to deal with. This guide gives realistic 2026 figures for Dover and East Kent, and explains what drives the price so you can judge a quote sensibly.
Typical price ranges
- Herbicide treatment programme (with guarantee): around £2,500–£5,000, spread over several seasons
- Excavation and full removal: around £5,000–£15,000+, depending on size and access
- Survey and management plan: often £250–£700, sometimes credited against works
These are ranges, not quotes. Only a survey gives a firm figure, because the variables below move the price significantly.
What drives the price
- Size of the stand. A small clump is far cheaper to deal with than an established, widespread infestation.
- Treatment versus excavation. Herbicide is cheaper but takes seasons; digging out is fast but costs more.
- Access. On Dover's terraced and hillside plots, getting machinery in is often the biggest cost factor for excavation.
- Waste disposal. Excavated knotweed is controlled waste and must go to a licensed facility, which carries a real cost.
- Proximity to buildings and boundaries. Knotweed near the house, drains or a neighbour's land needs more careful, and costlier, handling.
- The guarantee. An insurance-backed guarantee adds cost but is usually essential for a mortgage.
How to avoid overpaying
- Always get a survey and a written quote, never a phone estimate.
- Make sure any treatment quote includes an insurance-backed guarantee if you may sell or remortgage.
- Be wary of anyone quoting to dig it out before they have surveyed access and extent.
- Compare treatment and excavation quotes side by side — the cheaper headline is not always the better fit for your timescale.
The bigger picture
Knotweed rarely goes away on its own, and DIY attempts usually spread it. Dealt with professionally, it becomes a documented, guaranteed situation a lender will accept. For most owners, that certainty is the whole point.
Request a free survey for a firm price on both routes with no obligation.
Frequently asked questions
What is the cheapest way to deal with knotweed?
A herbicide treatment programme is usually the lowest-cost route, from around £2,500 to £5,000 including a guarantee, spread over several seasons. Excavation is faster but more expensive. The right choice depends on your timescale.
Does removal add value or just remove a problem?
Mostly the latter — it removes an obstacle to selling, remortgaging and insuring. Set against a stalled sale or a failed mortgage, the cost is almost always the smaller number.