Japanese Knotweed — A Focus for Action

What is Japanese Knotweed?

Japanese knotweed (Fallopia japonica) was introduced into Europe during the mid-nineteenth century as an ornamental plant. It has since become one of the most problematic invasive weeds in Europe.
Japanese knotweed is a perennial weed, producing tall canes up to 3m in height during the summer. The canes have characteristic purple flecks, and produce branches from nodes along its length. The branches support shovel shaped leaves and clusters of white flowers in autumn. The canes die off in winter,turning brown and shedding their leaves. This produces a dense mulch that precludes the growth of native species


How Does Knotweed Spread?

Japanese knotweed canes grow from dense crowns that also produce extensive underground stems called rhizomes. These can produce new plants and research has shown that rhizomes can penetrate the ground up to 3m and spread 7m laterally. Roots are very destructive to tarmacadam, brickwork, drains and foundations.
Japanese knotweed is often spread from top soil imported on to site (fly tipping is reportedly a big issue in the UK), and from shard or slivers of stem created by trimming or flailing of knotweed in attempts to control it. A 5mm sliver of knotweed can generate a new plant.
Road verge flailing must be avoided as it can create linear infestations along the road treated as we have in Glounthaune.

Our Knotweed Survey Results

In September, Glounthaune Tidy Towns undertook an extensive survey of Knotweed between Bury’s Bridge and Killacloyne to ascertain the extent of the problem in Glounthaune. The results were astounding.
We catalogued 0.6 Hectare in 76 individual stands with a distinct linear infestation along the railway and road. We estimated over 176000 stems need treating. We calculate 98% of knotweed is on land in public ownership managed by Cork County Council and Iarnrod Eireann.
This is not a new problem for Glounthaune. We have documentation showing we highlighted knotweed infestations to Iarnrod Eireann as early as 1991, In addition we have been fighting an infestation around the Ashbourne pond for six or seven years.

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How Can Knotweed be Controlled?

Eradicating knotweed is difficult, time consuming and expensive. The London Olympic site spent over £80M controlling knotweed in a scheme where tall rhizomes were excavated, sorted from the spoil and then buried and covered with a membrane!
Using a herbicide with appropriate controls is effective. Foliar (foliage) spraying requires several applications to be effective and can take 3 years of repeated spraying. A more effective treatment is stem injection – here one injects each cane like stem with a small amount of herbicide at the end of the summer. We invested in a stem injector and experimented in three locations at the end of last summer The results will be seen at the end of this spring. This is just a very good solution, especially for waterside locations and prevents collateral damage. We will use foliar spraying where accessibility is an issue on health and safety grounds and stem injection in all other cases.

Our Proposal to Cork County Council

We have proposed that Tidy Towns will manage a knotweed eradication plan in partnership with Cork County Council. We have proposed a budget and we await a positive response. Once this is in place we will approach Irish Rail and the National Roads Authority for action on their Knotweed infestations.
The complete eradication of knotweed will require a multiyear effort and take several years commitment by all to eradicate it from our community.

Can I help?

There are many ways in which you can help:

  • Look around your property for knotweed and commence a treatment plan. We have a stem injector for hire.
  • Do not cut, strim or flail knotweed – as it can rapidly spread. Cork County Council have been approached to alter their roadside maintenance approaches
  • Call Garry on 086 231 3963 to add any new infestation to our survey map
  • Do not remove soil from any knotweed infested site and be aware of the source of any imported top soil
  • Only dispose of knotweed to a licensed site – this is a legislative requirement! We have not found one yet…..
  • Call your TD and County Councillors and make them aware of YOUR concern over this scourge
  • Volunteer to help with stem injection when this commences in the summer


Knotweed effects us. all Please join with us to eradicate it from our community

Glounthaune Tidy Towns Projects for 2015


  • Extensive landscaping around new village signs
  • 1000m of roadside beech hedging on approach road
  • Whitethorn hedge near railway bridge to village
  • Wildflower meadow in Cuddy’s acre
  • Wildflower meadow in Johnstown ‘triangle’
  • Investigate possible landscaping estuary side of village behind the Rising Tide
  • Landscaping both sides of Johnstown entrance road from ‘main Road
  • Seating in Dry Bridge landscaped area

Ashbourne Pond

  • Flow to Ashbourne Pond reinstated
  • Bronze sculpture of Black Tailed Godwit at Ashbourne Walkway
  • Natural wood tables and seats


  • Glounthaune National School road marking to promote traffic calming
  • Intergenerational Quiz – transition year students from St Als Carrigtwohill
  • Participation at ‘ La Glas ‘ at Gaelscoil Ui Drisceoil


  • Lead group – Pride of Place representing South Cork in national competition
  • Expansion of village community herb garden
  • Organise waste reduction – energy reduction seminar in Centre
  • Promote Scouts Christmas Tree recycling
  • Promote establishment of Men’s Shed
  • Harpers Island Birdwatching Centre – promote the project
  • Biodiversity action plan
  • Coast Watch Clean Up along Rising Tide frontage
  • Knotweed survey, pilot usage of stem injection method, ongoing support of Cork Co. Council, year 1 of three year proposed eradication programme
  • Street lighting from Johnstown Park to the Church and roadside margin reinstatement

Tidy Towns


  • Two village signs in the form of Dry Bridge replica
  • Glounthaune National School road marking to promote traffic calming
  • Erection of Tidy Towns public notice board
  • New Co Council ‘Glounthaune’ road sign on Approach from Caherlag
  • Townlands carved stone identification markers

Craigs Field

  • Natural wood tables and seats.
  • Investigate feasibility of Walkway/cycle way along estuary from Craig’s Field to Little Island possibly following the approximate original ‘Crompan’ route.
  • Promote wildlife habitat at Eastern end of Craig’s Field – Bug Hotel

Glounthaune Tidy Towns Planning Letter Jan 2015 14/6679


We wish to make the following observations re the proposed development by O’Mahony
Developments at Johnstown, Killahora, Glounthaune.

1. The existing traditional stone wall (along the southern boundary of the proposed
development adjoining the roadway between Glounthaune and Carrigtohill) is of
significant interest and merit and should not be obscured, modified or removed
by the proposed works. It features a relatively unique ‘double’ wall, pictured
below, the top section being set back somewhat in a very individualistic and eyecatching
way. We regard this as part of the heritage of Glounthaune This is much
appreciated locally and has been the subject of many positive comments by locals,
passersby and visitors.
The existing wall and hedgerow provides an important linking habitat and a relatively
safe passageway for local fauna moving between locations.
We are also concerned that the replacement of the existing natural dry stone wall and
associated hedgerow on the eastern boundary will be replaced by a constructed wall,
again weakening the ecological corridor.
We also note that Cork County Development Plan 2014 opposes situations where
“excessive length of roadside hedgerow and trees to be removed”, we are of the
opinion that this situation applies here.
We would require any hedgerow being removed or degraded to be replaced in an
identified, defined manner clearly set out in the development proposal which would
also be amenable to external monitoring.



2. Glounthaune is located in the Metropolitan Cork Greenbelt and has a distinctive
village character often remarked on by visitors and passersby. Any housing developments
should reflect the village character and not detract from it. The current
proposed development and potential follow on phases, will conflict severely
with the village character on the basis of scale, layout and design. We note that
the Cork County Development Plan 2014 RC-I 5-8 states that it strives to “prevent
linear roadside frontage development on roads leading out of towns and villages”.
Thus we want the scale of the development to be reduced, setting back
the houses further from the roadway, thus allowing space for appropriate landscaping
inside the southern boundary, screening the housing units from the secondary
road and preserving the natural frontage and visual aspect. The south
sloping site on which the proposed development is located is exposed to the road
and is in a visually sensitive location along the approach to the village from the
In addition, the main entrance should be relocated to the minor road thus improving
the screening of the development and avoiding adding another traffic junction. The
minor road to the south of the relocated entrance should be widened as part of the
Planning Conditions.

3. We are concerned that the development will negatively impact on the nearby
Great Island SAC (1058) and the Cork Harbour SPA (4030). The Ecological
Survey Report Document No. 6102RP02 does not adequately address potential
disturbance by human activities, noise and illumination. We say that the zone of
impact of the proposed development will disturb the wintering birds. The Cork
County Development Plan 2014 requires that “developments will not affect the
bird population or distribution” of SACs or SPAs. We also note that the Cork
County Development Plan 2014 states that “the overall capacity of the Cork
Harbour SPA to absorb increased human activity has not been assessed”. We request
that this assessment be carried out prior to any Planning Decision to allow
a more scientific assessment of human impacts. We attach a copy of “Surveys of
waterbird numbers at Harper’s Island, Glounthaune, Co. Cork”, May 2014 Birdwatch
Ireland. This highlights the international importance and sensitivity of the
area directly across the road to the south of the development. A very significant
wildlife/educational amenity is being planned for Harper’s Island supported by
Glounthaune Community Association, Birdwatch Ireland and Cork Co. Council.
This would be accessed via the new railway bridge over the Midleton line.
We request that car parking spaces and one bus parking space be made available in
the proposed development, accessed via the minor road and behind the screening
landscaped area earlier mentioned in this submission. This would service the proposed
Harper’s Island facility.

4. The traffic count data presented as Turning Count Movements appeared somewhat
low to some local residents. the count was repeated on 21st Jan 2015 for the
same periods 0800-0900 and 1700-1800.
the results were as follows:

Due to the large order of magnitude discrepancies, we suggest that the traffic count
data be rechecked and repeated by the developer before any planning decision is
made. The recent opening of the Killahora Amber filling station (low cost motor
fuel), increased employment in Little Island (greater proportion using the Glounthaune
to Little Island access), and some morning traffic disruption at the N25 exits
are likely to have contributed to the large increase in usage of the secondary road adjacent
to the proposed development (especially the morning count).


Traffic Movements

5. We would like to point out that the Glounthaune Railway Station Car Park is always
full with the overflow parking along the roadside margin in an unsuitable location.
This unregulated parking beside a busy road compromises road safety. A typical
day (21st Jan 2015) is shown below:



Road Side

Road Side

We also do not agree that the proposed Park and Ride at the planned new Dunkettle
Railway Station will do anything to alleviate the Glounthaune Station parking. It is
accepted widely that train passengers arriving by car will choose the local most convenient
station and will not drive further than necessary to park.
Thus we submit that the development should not go ahead until the Glounthaune
Railway Station Car Park capacity is extended. !
6.We note that the proposed development does not include in the drawings the proposed
cycleway/walkway linking Carrigtwohill and Little Island Station. Sections of
this are already completed and the link between Killacloyne Bridge and Johnstown
Park are awaited. It would run on the road margin along the southern boundary of
the development. Full provision should be made for this in any development alongside
the roadway.
Please find enclosed the €20 fee.
Yours Sincerely,
Conor O’Brien
Chairman Glounthaune Tidy Towns




Contact & Committee