Japanese knotweed

23 April, 2025

What Does Japanese Knotweed Look Like?

Japanese knotweed changes its appearance throughout the year, which can make it tricky to identify unless you know what to look for.

In spring, reddish-purple shoots that resemble asparagus start to appear, quickly giving way to tall, bamboo-like canes dotted with purple flecks. By summer, the plant becomes bushy and dense with large, bright green, spade-shaped leaves arranged in a distinctive zigzag pattern along the stems. Small clusters of creamy-white flowers bloom in late summer, often standing out starkly against the green foliage.

Come autumn and winter, the plant dies back, leaving behind brittle, hollow canes that persist above ground — these remnants can be just as telling as the fresh growth.

Why It Matters When Selling

If Japanese knotweed is found on your property, it’s not something you can ignore. Under UK law, you must disclose its presence when completing the TA6 Property Information Form. Failing to do so can result in costly legal claims down the line.

Mortgage lenders often require proof that a professional treatment plan has been initiated. DIY methods aren’t enough — knotweed rhizomes can grow metres underground and regenerate from a tiny fragment. That’s why most buyers (and lenders) look for treatment carried out by PCA-accredited specialists, backed by a 10-year insurance guarantee.

If you're selling, transparency is your best policy. Provide your buyers with detailed documentation about the knotweed, the treatment programme, and any guarantees.

What Buyers Should Watch For

Viewings aren't just about checking the size of the kitchen or the orientation of the garden. If you're in the market to buy, keep an eye out for signs of knotweed — both on the property and on neighbouring land. Its roots can spread from next door, and that proximity still affects your purchase.

Always ask direct questions, check the TA6 form for disclosures, and if in doubt, invest in a professional knotweed survey.

Quick Reference: Japanese Knotweed Guide

Here’s a handy table summarising what to look for and what to do whether you’re buying or selling:

Japanese knotweed might be persistent, but it doesn’t need to ruin your property plans. With the right knowledge, a proactive approach, and professional support, you can manage its impact whether you're preparing to sell or searching for your next home.

If you're unsure how knotweed could affect your sale or purchase, speak to one of our team at Get An Offer.  We're always here to help make the process clearer and stress-free.