Phenology and long-term control ofHeracleum mantegazzianum

The growth characteristics and reproductive capacity are described for Heracleum mantegazzianum, an invasive perennial plant that has significantly increased its geographical range in Ireland in recent years. The effect of cutting on growth and seed production is described. Based on research findings, a detailed Giant Hogweed control programme is presented which could result in the elimination of the plant. A Giant Hogweed eradication programme on the Mulkear River catchment (c. 670 km2), using this protocol, commenced in 1998 and will continue until 2002.