Why winter is the best time to commission a knotweed survey for 2026 treatment
Late winter is the quietest time in our diary — and the surveys we do now feed straight into a first treatment in April or May.
Most homeowners book a knotweed survey in July when the plant is unmissable. But late winter — January and February — is often the better window, both for the survey itself and for getting in front of the spring rush.
What we can see in winter
Standing dead canes from last summer's growth are obvious in a leafless garden. The crown at ground level is clearly visible. We can map the extent of the rhizome run by probing around the base, and we can identify look-alikes (ornamental bamboo, dogwood) with the same confidence as we would in July.
Why time it for 2026
Year-one treatment starts properly in April or May when the plant is in active growth. A January survey gives us the planning lead time to schedule the visit, prepare the IBG paperwork and clear the herbicide order. Spring instructions often slip to a year-two start because the diary is already full.
Mortgage and conveyancing timing
Buyers and sellers exchanging in spring 2026 benefit from having a winter survey on the file. It is a cheaper survey (shorter site visit, easier access) and the resulting plan can be activated the moment the weather warms.
Reviewed by
The survey team
PCA-certificated surveyors, Japanese Knotweed Elimination
PA1 / PA6A certificated surveyors who carry out the site visits, write the management plans and sign off the reports issued to lenders and solicitors.
Reviews the technical, legal and lender statements in this article.
What this page can't tell you
- Guidance is general. Identification, treatment choice and timescales can only be confirmed by a site visit — photographs alone are indicative.
- Lender and insurer requirements vary by institution and change over time. We state what is typically accepted, not what any named lender will accept on your case.
- Guarantee (IBG) eligibility depends on the plan chosen, the survey findings and the underwriter's acceptance. It is not automatic.
- Legal points summarise published law and guidance current at the review date. They are not legal advice.
Last reviewed · Questions on anything stated here: 07582 869979
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