Clonakilty Knotweed talk draws big attendance

PEOPLE travelled from as far away as Bantry and Bandon to last weeks public talk organised by Sustainable Clonakilty on the subject of Japanese Knotweed which was held in O’ Donovan’s Hotel. Guest speaker on the night was Conor O’ Brien, a member of the Glountane Tidy Towns Group, which has undertaken a major project in recent years in their area to rid public areas of the invasive weed.

Conor illustrated via slides of the prevalence of Japanese Knotweed along several kilometres of the old Cork to Glountane roadway and also along the Cork to Cobh rail line.

The common Japanese Knotweed is a major invasive plant that multiplies rapidly. It should never be cut or dug up and the only real way to ensure it is eliminated is by chemical treatment over a period of years. This is costly, labour-intensive and time-consuming.

Conor outlined how his group was supported by TÚS workers and the local county council officials, which combined with the Tidy Towns volunteers who took on the problem several years ago. Through research, they found that the most effective way to eliminate the weed was to inject pure Roundup into the stalks of the plants in the autumn, using special hand-held injection guns. Every single stalk needs to be treated to ensure success.

This treatment needs to be repeated for up to three years to ensure that the chemical is absorbed into the root system completely and kills off the growing cells. Otherwise the plant can recover and colonise an area quickly again, negating the work undertaken in Year one.

Conor stressed that the smallest bit of live stem can sprout to start off a new plant, and therefore Japanese Knotweed should never be cut, regardless of how careful the person intends to dispose of the cut stems. Likewise, digging up living roots is a fairly futile action.

He said how the process in Glountane has cost over €8,000 to date but has been recognised as having a very positive affect on the population of the destructive plant which can burst up through concrete and tarmac and unsettle foundations.

An interesting question and answer session ensued with no one under any illusion at the end of the enormous challenge that this pest is and the need to be vigilant in ensuring that it is treated in any place as soon as it is seen.

In public areas, like roadside verges, etc. it should be reported to the County Council who will mark it and treat it professionally at the correct time of the year.

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