Advice as Japanese Knotweed hotspots in Merseyside confirmed

The weed can cause damage to buildings and structures2025 Japanese knotweed hotspots in Merseyside (Image: Environet)

As the weather takes a brighter turn, many of us will be making the most of our gardens and green spaces. One thing gardeners don’t want to see is invasive plants such as Japanese Knotweed. The invasive perennial weed that is fast-growing and can cause damage to building and structures.

Invasive plant specialist Environet has revealed Merseyside’s knotweed hotspots for 2025 using the latest data from its online tracker. There are a total of 2,963 verified knotweed sightings in Merseyside, making the region the second worst affected area after Bristol.

Knotweed begins to emerge in early spring, quickly growing into lush green shrubs with pink-flecked stems, heart-shaped leaves and bamboo-like canes.

The plants can create serious problems for homeowners, with underground rhizomes that can grow up to three metres deep and spread up to seven metres horizontally.

These can then emerge through cracks in concrete, tarmac driveways, pathways, drains and cavity walls.

Merseyside’s top 10 Japanese knotweed hotspotsLiverpool – 797 incidencesSt. Helens – 683 incidencesSouthport – 233 incidencesNewton-le-Willows – 221 incidencesHuyton with Roby – 167 incidencesPrescot – 140 incidencesHaydock – 134 incidencesBootle – 121 incidencesKirkby – 98 incidencesWhiston – 78 incidences

Environet Director Emily Grant said: “By mapping verified sightings, we’re helping people understand the level of risk in their local area and encouraging early identification and treatment.

Japanese knotweed(Image: Barry Batchelor/PA Wire)

“Vigilance is the best way to protect your property from Japanese knotweed, making sure you tackle it as early as possible before it becomes well established.

“At this time of year, knotweed is in full growth mode and easy to spot with its bright green heart-shaped leaves which grow in a zigzag pattern up the stems. Mature plants flower around August, when they produce clusters of tiny white blooms.

“If you do suspect you have knotweed on or near your property, you can email a photo to us at expert@environetuk.com and we’ll identify it for free.

“If it is knotweed, a survey will determine the extent of the infestation and the best way to treat it, whether that’s digging it out of the ground, herbicide treating it or a combination of both.

“Public engagement is key in the fight against knotweed, and by reporting new sightings homeowners can play an important role in controlling this invasive plant and protecting property values.”

Further information can be found here.