Phenology and long-term control of Heracleum mantegazzianum

The growth characteristics and reproductive capacity are described for Hera cleum mantegazzianum, an invasive perennial plant that has significantly in creased its geographical range in Ireland in recent years. The effect of cu tting on growth and seed production is described. Based on research finding s, a detailed Giant Hogweed control programme is presented which could resu lt in the elimination of the plant. A Giant Hogweed eradication programme o n the Mulkear River catchment (c. 670 km(2)), using this protocol, commence d in 1998 and will continue until 2002.