Japanese knotweed is a highly invasive plant species that can cause significant problems in the UK. It is capable of growing in most soil conditions found in the UK, particularly in man-made habitats such as roadsides, waste ground, and railway embankments.
Knotweed spreads through direct rhizome (root) growth and new plant growth from the parent plant’s stem and rhizome fragments. A new plant can grow from pieces of rhizome as small as 1cm.
The rapid growth and spread of knotweed can cause damage to buildings, roads, and other structures. Its roots can grow through concrete, asphalt, and other hard surfaces, causing cracks and other damage. In addition to the physical damage it can cause, knotweed can also reduce property values and make it difficult to sell a property that is affected by the plant.
If you have knotweed on your land or property, you must take steps to prevent it from spreading off your property. Soil or plant material contaminated with knotweed can cause ecological damage and may be classified as controlled waste. You do not legally have to remove Japanese knotweed from your land unless it’s causing a nuisance, but you can be prosecuted for causing it to spread into the wild.
There are several ways to stop knotweed from spreading, including spraying or injecting the stems with chemicals. However, this process usually takes at least 3 years and requires careful management to ensure that the knotweed does not regrow. It is important to work with a professional who has experience treating knotweed to ensure that the problem is effectively addressed. In summary, Japanese knotweed is a significant problem in the UK due to its ability to grow rapidly and cause damage to buildings and other structures. It is important for property owners to take steps to prevent the spread of this invasive plant species. Japanese knotweed can also have a significant impact on house prices in the UK. According to a study by Environet UK, knotweed has knocked £20 billion off the total value of the UK property market1. It is estimated that between 850,000 and 900,000 UK households are affected by the Japanese plant, wiping almost £20 billion off UK house prices1. Many mortgage lenders refuse loans for properties affected by the weed1. Knotweed can reduce a property’s value by between 5-15% and depending on the size of the infestation and its proximity to surrounding buildings, it could even make a property unsellable2. Sellers are now required to inform future buyers whether the property is or has been affected by Japanese knotweed even if it the plant has been removed1.
Knotweed Education UK 