Rhododendron - Rhododendron ponticum Biodiversity High Risk

Reproduction: It can reproduce by both sexual (seed) and asexual (vegetative) means. Each flower head can produce unto 7,000 seeds.

Rhododendron seeds can be dispersed by wind up to 100 metres.

It is also capable of reproducing by suckering from roots and by layering wherever branches touch the ground.

Rhododendron - Rhododendron ponticum Flower Petals

Rhododendron Flower

Rhododendron is a large perennial evergreen, acid loving shrub which is native to the Iberian Peninsula and Asia. It was introduced to Ireland during the 18th Century as an ornamental garden plant because of its attractive flowers.

There are over 900 species of Rhododendron, but only Rhododendron ponticum is invasive in Ireland.

Since its introduction, Rhododendron has escaped into the wild and is particularly invasive in the west, north-west and south-west of the country. Rhododendron thrives on acidic soil in areas with mild, moist climatic conditions.

It can colonise a range of habitats including agricultural land, grasslands, woodland, urban areas, roadsides and wastelands

How To Identify Rhododendron?

Flower: Purple flower

Leaf: Deep green waxy leaf

Stem: Woody and tangled

Rhododendron - Rhododendron ponticum Large Stand

Rhododendron - Rhododendron ponticum Leaf and Flower Bud

Rhododendron invasive stand

Rhododendron - Rhododendron ponticum ID Guide

Rhododendron leaf

Why Is Rhododendron A Problem?

Rhododendron is an aggressive coloniser which is both environmentally and ecologically damaging to infected sites.

Once established, it forms dense, long-lived thickets which smother the ground flora and suppress the regeneration of native trees and shrubs. Its dense thickets can reach several metres in height.

Well established thickets eventually form a toxic layer of leaf litter which produces a dark sterile environment and supports little wildlife.

The foliage of Rhododendron is unpalatable to grazing animals. Dense tangles of Rhododendron stems can block pathways, smother watercourses and encroach on roadways, resulting in an impingement of sight- lines.

In some cases, infestations have been so expensive to control that land has been abandoned.