What Does Knotweed Look Like?

Knotweed is one of the most invasive plants in the UK, growing and spreading rapidly over large areas. It is important that people are able to identify it so they can prevent it from taking over their gardens and surrounding habitats. The appearance of knotweed can vary depending on the season, but there are a few things that can help to distinguish it from other plants and shrubs such as lilac and common dogwood.

The first thing to look for is the shape of the stems. They usually start out as a reddish/purple shoot at the beginning of spring looking similar to asparagus with a reddish colouring. However, as they grow throughout the spring and early summer they become more green with purple specks and raised nodes along the stem giving it an appearance similar to bamboo. Once the plant reaches maturity in late summer they can grow to up to 2-3 metres tall.

As well as the stems, the leaves are also a key feature to look out for. They are bright green and heart shaped with a zig-zag pattern – they can reach up to 14cm long. The leaves can be rolled back at the tips which adds to their overall appearance of a bamboo-like stem.

If the leaves and stems are cut or mowed by mistake, the cuttings will likely re-sprout into new what does knotweed look like plants. Therefore, the best way to prevent knotweed spread is by not removing any part of the plant.

Although it is tempting to use garden equipment such as weed trimmers on knotweed, this is very damaging and should be avoided at all costs. Even if the roots are trimmed, they can still regrow a whole plant elsewhere in the garden, and the cuttings themselves can easily be moved by water or people and end up on different sites where it can then take root again.

It is also recommended to avoid mowing or using hedge trimmers on knotweed, as this can cause it to break off and grow in a new area. Chemical controls such as herbicides are the only way to effectively control knotweed and it is essential that they are used in a safe manner and in accordance with any relevant environmental permits.

Japanese knotweed is not only detrimental to the environment but it can also cause structural damage to buildings. It is therefore crucial that people can spot it and have it treated by experts in order to stop it causing harm. This is particularly important for properties in urban areas where it can spread to buildings and cause serious structural damage, affecting the value of the property. It can also affect the ability of property owners to get buildings insurance. The insurers will often only pay out if the owner can prove they have done everything they can to prevent the spread of the weed. This is why it is important that people check for knotweed regularly, especially in spring and summer when the plant is at its most active.