Return of the Natives

Hottentot Fig (Carpobrotus edulis) is a popular garden plant from South Africa (right). unfortunately it is also an aggressive invader of coastal habitats, where it forms vast mats to the exclusion of all other plants. It poses a serious ecological threat to the coasts of Ireland.

In 2007 the National Botanic Gardens began a project to control and ultimately eradicate Hottentot fig from Howth Head. The plant has been present since 1962 and has grown into patches up to 40 metres across. More recently it has been appearing at numerous other sites along the coast, demonstrating that it was actively spreading on Howth.

In 2010 the Heritage council awarded a Biodiversity grant to the National Botanic Gardens which enabled us to actively combat this plant before it became unmanagable. By August of this year, Noeleen Smyth, who is spearheading the project on behalf of the gardens, was able to report a double success - not only is the plant hugely reduced in numbers (a 97% kill rate); but the native flora of the cliffs has reappeared in huge numbers and some 20% of the areas previously dominated by Hottentot Fig are now covered by regenerating Sea beet, Rock Samphire and Golden Samphire (see below). The speed at which this has taken place gives us great hope that by acting quickly we have averted a known Invasive Alien from gaining a permanent foothold in ireland.

You can read more about the project on our resarch pages here ...

The project team wish to thank the Heritage Council for providing the funding to carry out both the pilot control project in 2010 at Howth Head, and further work across the country in 2011. We would also like to thank Ann Murphy, Hans Visser, Deborah Tierney and Florence White of Fingal Co. Council, the members of the Howth Committee, Maurice Eakin and Niall Harmey of NPWS, and the support of the Invasive Species Ireland project which co-ordinates efforts to prevent and control invasive species in ireland.

Rock Samphire (Crithmum maritimum) regenerating through a mat of killed Carpobrotus at the Baily Lightouse. September 2011	Golden Samphire (Inula crithmoides), with Rock Samphire at top and Sea Beet (Beta maritima) below, at Lion's Head. September 2011.