We’ve been keeping a lookout for the first Japanese knotweed shoots of the season and we can confirm they’ve been spotted by our eagle-eyed Regional Director, Emily, on the banks of the River Plym in Plymouth, Devon. This means knotweed has officially begun its spring growth season and will emerge in gardens, parks, verges and riverbanks up and down the country over the next few weeks.

Japanese knotweed hibernates during the winter months before emerging when the ground temperature reaches around 4°c, usually in March or April. Red or purple asparagus-like shoots sprout from the earth and quickly turn into green bamboo-like stems, growing at a rapid rate to reach approximately 3 metres in height by June.

Homeowners should be vigilant for the distinctive spear-like shoots emerging in their gardens or near their homes as the knotweed growing season becomes established. If you’ve seen a suspicious new plant in your garden and you’re worried it could be knotweed, email a photo to us at [email protected] and we’ll confirm what you’re dealing with.

Those who discover the plant on their land should seek professional advice and put a treatment plan in place as quickly as possible, to preserve the value of their property and to protect themselves from the risk of litigation if the plant is allowed to spread.

While herbicide treatments require the plant to be in full leaf, usually around May, it isn’t necessary to wait as knotweed can be removed at any time of year using our environmentally friendly Resi-Dig-Out™ method. This involves digging out the rhizome roots and sifting out every viable piece before returning the clean soil to the ground. A 10-year insurance-backed guarantee is provided for the treatment, underwritten by a “AA-” rated insurer, ensuring the property can be bought or sold without difficulty.

You can also report the sighting on Environet’s Japanese knotweed heatmap, Exposed, a live tracker monitoring knotweed sightings across the UK. Just enter your postcode to discover the number of reported knotweed infestations nearby, with hotspots clearly visible in yellow or red. Report knotweed infestations using the ‘Add Sighting’ feature and attaching a photograph of the plant so it can be verified by our experts.