Natural England Cornwall, a government agency body of DEFRA responsible for promoting natural conservation and protecting biodiversity across the county’s three National Nature Reserves (NNRs), has been an active supporter of stem injection treatment since purchasing its first unit from Stem Injection Systems in 2013.

The reserves, all special areas of conservation and sites of special scientific interest, comprise the steep-sided wooded valley of Golitha Falls, the flat valley basin of Goss Moor and a number of isolated coastal grasslands and heaths on the Lizard Peninsula, a famous 2,000 hectare site at the most southerly part of the British mainland.

Varying degrees of Japanese Knotweed growth has been a problem, especially at Goss Moor where historic cases of fly-tipping and illegal land fill, compounded by its rapid spread along a railway corridor, had caused a number of problem knotweed stands to grow. Treatment work initially started by Cornwall Council has been taken up by the Natural England team, with its realistic objective being one of containment rather than outright eradication.

Led by Phil Bowler, senior reserves manager covering NNRs in Cornwall, the treatment team has mapped all knotweed hotspots and recorded progress of the stem injection programme, enabling it to monitor treatment success. Historically, conventional spraying had been carried out but this was considered too indiscriminate in targeting specific areas and too slow to achieve tangible results.

Phil commented: “The National Nature Reserves in Cornwall are some of the best places in the country for diverse wildlife species, rare plants and exciting natural habitats, which is why we prefer to avoid whole area techniques in favour of localised spot treatments such as stem injection.

“Over the past three years we have enjoyed excellent success with the stem injection system, with most of the major knotweed stands significantly thinned out and seasonal regrowth now noticeably kept to a minimum. Obviously environmental responsibility is a primary concern and, since stem injection avoids spray drift, we can minimise any adverse impact not just on plants and wildlife but also on the safety of the general public, dogs being walked and livestock.”