Winter Heliotrope
(Petasites pyrenaicus, previously P. fragrans) – Plúr na gréine
Winter heliotrope, a member of the Asteraceae family, is a low-growing herbaceous plant native to the Mediterranean region. It was introduced as ground cover but has spread rapidly. It is established widely in Ireland, particularly in the south of the country. A shade-tolerant species, it is frequently found along roadsides, railway banks, river banks, hedgerows, woodland edges and waste ground.
Distribution
(National Biodiversity Data Centre, Ireland, Winter Heliotrope (Petasites fragrans), image, accessed 24 June 2022)
Winter Heliotrope (Petasites pyrenaicus)
Classified as a low impact invasive species by the Irish National Biodiversity Centre. Not a Third Schedule listed species under Regulations 49 & 50 in the European Communities (Birds and Natural Habitats) Regulations 2011.
Established
Identification:
- Winter Heliotrope is a short, herbaceous, perennial with large heart-shaped leaves up to 20cm in diameter with regular serration along the margins.
- The foliage appears later in spring (although last year’s foliage may not die back completely) and forms a dense carpet to circa 20cm in height.
- Its pale pink flowers, which are amongst the earliest flowers of the year, appear in December and January and have distinctive smell.
Reproduction:
Winter Heliotrope is a clonal species and as only the male plant has been recorded in Ireland, its spread is confined to vegetative means. It spreads by rhizomes. Winter Heliotrope flowers in Winter, usually from November to February, with pale pink, sweet scented flowers.
Impacts:
Winter heliotrope forms large dense monocultures, which exclude native vegetation by shading out light. This leads to a decrease in biodiversity locally. It is believed that Winter Heliotrope is important as a food source for pollinators in winter months.
Treatment:
- Mechanical: Repeated mowing, cutting and strimming can be carried out to weaken the plant over time. The plant can also be covered up with wet cardboard, and light excluding bark mulch and left for a few weeks.
- Chemical: Herbicidal control can also be used at a later stage by applying a glyphosate herbicide through foliar spraying in dense stands and weed wiping in mixed stand during summer. This can reduce leaf cover.
More photos:
