--- title: "What Is Japanese Knotweed? | Isle of Wight Expert Guide" description: "What Japanese Knotweed is, where it came from, and why it is the UK's most destructive invasive plant. Expert Isle of Wight guide for homeowners." lang: en-GB json-ld: | [ { "@context": "https://schema.org", "@graph": [ { "@type": "Organization", "@id": "https://www.isleofwightjapaneseknotweed.com/#organization", "name": "Isle of Wight Japanese Knotweed", "url": "https://www.isleofwightjapaneseknotweed.com/", "areaServed": { "@type": "Place", "name": "Isle of Wight, United Kingdom" }, "knowsAbout": [ "Japanese Knotweed", "Invasive plant removal", "PCA treatment plans", "Insurance-backed guarantees", "RICS knotweed reports" ] }, { "@type": "WebSite", "@id": "https://www.isleofwightjapaneseknotweed.com/#website", "url": "https://www.isleofwightjapaneseknotweed.com/", "name": "Isle of Wight Japanese Knotweed", "publisher": { "@id": "https://www.isleofwightjapaneseknotweed.com/#organization" }, "inLanguage": "en-GB" } ] }, { "@context": "https://schema.org", "@type": "LocalBusiness", "name": "Isle of Wight Japanese Knotweed", "description": "Expert Japanese Knotweed identification, treatment and removal services across the Isle of Wight.", "url": "https://www.isleofwightjapaneseknotweed.com", "telephone": "+441983000000", "email": "info@isleofwightjapaneseknotweed.com", "areaServed": { "@type": "Place", "name": "Isle of Wight", "address": { "@type": "PostalAddress", "addressRegion": "Isle of Wight", "addressCountry": "GB" } }, "priceRange": "££", "openingHours": "Mo-Fr 08:00-18:00" } ] --- [](tel:01983509019) [![Isle of Wight Japanese Knotweed](/assets/logo-BKGpI34K.png) Isle of Wight Japanese Knotweed Experts ](/) [Home](/) [About Knotweed](/about-japanese-knotweed) [Treatment](/japanese-knotweed-removal-isle-of-wight) [Property Impact](/japanese-knotweed-property-impact) [Cost Calculator](/japanese-knotweed-removal-cost-calculator) [News](/news) [Get a Quote](/get-quote) [Get Free Quote](/get-quote) # What is Japanese Knotweed? Japanese Knotweed (Fallopia japonica) is an invasive perennial plant that can cause serious structural damage to buildings and significantly impact property values. ## Origins and History Japanese Knotweed is native to Japan, Taiwan, and northern China where it thrives on volcanic slopes. It was brought to Britain in the 1850s by the Victorian plant hunter Philipp Franz von Siebold, who sold it as an ornamental plant. Without its natural predators (insects and fungi that control it in Asia), the plant spread rapidly across the UK and is now found in every county, including throughout the Isle of Wight. ## Physical Characteristics ### Above Ground - Hollow, bamboo-like stems - Purple/red speckled canes - Heart-shaped leaves up to 20cm - Grows up to 3 metres tall - Cream/white flowers (Aug-Sept) ### Below Ground - Rhizome network up to 3m deep - Spreads 7m from visible plant - Can remain dormant for 20 years - 0.7g fragment can regrow - Breaks through concrete/tarmac ## Why is Japanese Knotweed a Problem? Japanese Knotweed is classified as one of the world's 100 worst invasive species. In the UK, it causes an estimated £166 million in damage annually. The problems include: - **Structural damage:** Roots can exploit cracks in foundations, drains, and walls - **Property devaluation:** Reduces values by 5-15% on average - **Mortgage refusals:** Many lenders won't lend on affected properties - **Legal liability:** You can be sued if it spreads to neighbours - **Disposal costs:** Must be disposed of as controlled waste [Identification Guide](/japanese-knotweed-identification)[Get Free Survey](/get-quote) ## Next steps with Isle of Wight knotweed specialists Explore the services most Isle of Wight homeowners, buyers and landlords go to next: - [free Japanese Knotweed quote](/get-quote) for your Isle of Wight property, with a local specialist response within 24 hours. - [Japanese Knotweed survey Isle of Wight](/japanese-knotweed-survey-isle-of-wight) — RICS-compliant identification, management and mortgage reports booked within 48 hours. - [Japanese Knotweed removal Isle of Wight](/japanese-knotweed-removal-isle-of-wight) using herbicide, excavation or combined methods with a 10-year insurance-backed guarantee. - [Japanese Knotweed treatment cost Isle of Wight](/japanese-knotweed-treatment-cost-isle-of-wight) — honest 2026 pricing for every treatment option, with no hidden fees. - [Japanese Knotweed removal cost calculator](/japanese-knotweed-removal-cost-calculator) for an instant estimate tailored to your infestation size and access. - [10-year insurance-backed knotweed guarantee](/japanese-knotweed-guarantee) — transferable to new owners and accepted by every major UK mortgage lender. PCA Members Property Care Association RICS Approved Certified Specialists 10 Year Guarantee Insurance Backed Fast Response 48hr Survey Booking [ JK Isle of Wight Japanese Knotweed ](/) Expert Japanese Knotweed identification, treatment and removal services across the Isle of Wight. We connect you with certified, local specialists. 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