Late season frosts and dry weather are set to put Japanese knotweed in pole position to take off across the UK.
Experts at the Property Care Association (PCA) say the weather this spring is changing the invasive weeds’ growth pattern.
For several years, the first flush of the plants’ distinctive asparagus-like red stems have emerged in March, a month ahead of its usual growing season – and according to the PCA, the pattern was on track again for 2021.
However, April’s frost and dry weather have pushed this early growth pattern off course but, despite this, Dr Peter Fitzsimons, the PCA’s Invasive Weed Control Group technical manager, says the climate conditions could make the invasive plant come back stronger than ever.
Dr Fitzsimons said: “Many plants in the UK have been knocked-back by late season frosts and dry weather in April, but the sheer resilience of Japanese knotweed means it will be in a position to come back even stronger.
“While almost every plant has struggled with the weather conditions, it’s likely that this will help Japanese knotweed to dominate even more that it normally does because it is such a resilient plant.
“When some warmer weather and spring rains come along, we are set to see it take off, using its food reserves stored below ground over winter.
“If it does dominate, simply put, that means more damage potential and capacity for the plant to spread.”
The presence of Japanese knotweed can devalue land and property and lead to the refusal of mortgages on properties affected by it.
It is considered a nuisance plant because it grows so rapidly and can cause disruption to and around buildings.
Dr Fitzsimons said: “Despite the issues Japanese knotweed can cause, it can be controlled and managed, in that it can be identified and treated with minimal impact, but its effective management is a job for the experts and the earlier that work takes place, the better.
“It’s a good idea for anyone who thinks they might have an issue to obtain a professional opinion.
“Currently, the law focuses on landowners to control and remediate Japanese knotweed infestations, particularly near houses, as soon as they come to light.
“In the case of property development, removal by excavation is often the only viable solution and this needs to be handled by qualified knotweed surveyors.
“Advice sought quickly will help to control and manage the situation effectively.”
The PCA’s Invasive Weed Control Group signposts the public and private sectors to professional specialist contractors and consultants.
The Association also has a library of information including guidance notes, information leaflets and a Code of Practice - all available for free download - to provide insight and guidance on the issue www.property-care.org/professionals/invasive-weed-control/invasive-weed-control-technical-document-library
