Overview

• Recent wet and warm conditions across the UK have triggered unusually rapid development of Japanese knotweed in gardens.
• Characteristic features include hollow, bamboo-like stems up to two metres tall, zigzag-patterned spade-shaped leaves and clusters of cream-white flowers.
• Under UK law landowners must prevent the plant’s spread and disclose any infestations when selling or face potential prosecution.
• Knotweed infestations can shave up to 15% off property values and may lead banks to withhold mortgages until treatment is guaranteed.
• Effective eradication demands professional herbicide programmes and excavation, with removal bills often running into thousands of pounds.