Ah Rhododendron season - a flood of eye popping, electric pink covers great swathes of Ireland’s landscape. Summer has arrived. At first glance, this is a beautiful show. But, look again. Look closer. Delicate, rare and ancient ecosystems are soon to be subsumed by this seemingly invincible plant. This is a terrible beauty. This is the story of Ireland’s catastrophic Rhododendron invasion - Read on to find out why it matters and what we can do.
If you visit the wilder parts of the Irish countryside, in the months of May and June, at some point you will encounter the most surreal blanket of purple and dark green. A flood of eye popping, electric colour set against an otherwise subtle palette of gentle brown and green hues. This extraordinary mass of colour is killing our native species and habitats right before our very eyes and it’s doing it in the most beautiful way.
Rhododendron (Rhododendron ponticum) is a non-native, invasive species in Ireland, first introduced in the 18th century. At that time it was planted in and around ‘The Big Houses” of the gentry and upper classes. Prized for its flamboyant and vibrant blooms it was planted as an ornament and to provide cover for game birds, namely pheasant (also an introduction originating from Asia).
A typical sight - Rhododendrons found growing on the grounds or ruins of a ‘Big House’.
Since the first introduction of Rhododendron, in the gardens of the 18th century ‘Big House’, much has changed in Irish life. Many of the ‘Big Houses’ and hunting lodges have been abandoned. Yet, this large evergreen plant lives on, thriving and fast growing in the acidic soils of the west of Ireland.
Particularly worrying is the fact that 18th century hunting lodges tended to be built in the wildest and most remote parts of the country. So, unfortunately, it is in these wild, natural landscapes that Rhododendron has taken a foothold. The waxy evergreen plant roams freely in Ireland's upland bogs, wild hillsides, native woodland and sensitive river valleys. Often it will be found growing along the banks of prolific salmon rivers or close to wild upland habitats suited to deer, grouse, or snipe. Most worryingly, Rhododendron now covers great swathes of our National Parks, lands which were granted special protections because of their ecological importance.
The waxy evergreen plant with its pink bloom roams freely in Ireland's upland bogs, wild hillsides, native woodland and sensitive river valleys
Why all of this matters is the fact that some of the most beautiful parts of our country are now under threat of this beautiful infestation. Rhododendron is a dense, dense shrub. Wherever it grows, the naturally balanced habitat of wild flowers and seedlings cannot compete and cannot survive. Delicate, rare and sometimes ancient ecosystems are under threat of being overcome by this seemingly invincible plant. Complex bogland with its innumerable tiny plant species are being transformed into pretty pink desserts.
As the plant spreads further and further it is wiping out unique ecosystems which survived due inaccessibility, difficult terrain or because the land was so lacking in nutrients that it was never farmed. The Rhododendron seeds are being swept on the wind to lake islands where they out grow Juniper trees which have been established there for hundreds of years. It is growing in a thick blanket through ancient Oak forests in Co. Kerry, smothering everything in its path. The result of this is Oak stands which have thrived for hundreds of years might now be the last generation to successfully reseed.
Hidden Houses
A flood of garden escapees
Most worryingly, Rhododendron now covers great swathes of our National Parks, lands which were granted special protections because of their ecological importance. Here Rhododendron can be seen both sides of the driveway to Wildlife Rangers head office in National Park at Ballycroy in North Mayo.
As the plant spreads further and further it is wiping out unique ecosystems which survived due inaccessibility and difficult terrain or because the land was so lacking in nutrients that it was never farmed.
Eradicating a Rhododendron infestation is no mean feat. But even with decades of hard work, fastidious record taking and a systematic approach it is a battle. My fear is we are losing that battle.
Here’s what you can do:
Read more about Ireland’s battle with Rhododendron investigation below and if you can, donate to the Irish Wildlife Trust, details below.
Charities:
-Ground Work is a voluntary environmental organisation, dedicated to the preservation of some of Ireland's most precious habitats. -http://www.groundwork.ie
-Irish Wild Life Trust- aims to conserve wildlife and the habitats they depend on throughout Ireland while encouraging a greater understanding and appreciation of the natural world and the need to protect it. You can Donate here.- https://iwt.ie/donate/
New Paper Artcles:
Rhododendron: An ecological disaster in Killarney National Park, Paddy Woodworth, May 18, 2019 The Irish Times.
Citation:
Higgins, G.T. (2008) Rhododendron ponticum: A guide to the management on nature conservation sites. Irish Wildlife Manuals, No. 33. National Parks and Wildlife Service, Department of the Environment, Heritage and Local Government, Dublin, Ireland. LINK.