The genus Heracleum is comprised of 60 species of biennials and perennials from mountainous areas, including the Himalayas and Ethiopia. Their most distinguising features are their statuesque presence and their large, flat or rounded flowerheads. Leaves are deeply cut. Grow cow-parsnip in a border or wild area where its form can be appreciated.
Noteworthy CharacteristicsStatuesque form. Large flower clusters. H. mantegazzianum is toxic if eaten and its sap can cause dermatitis. It is a U.S.-listed noxious weed and is banned in some areas.
CareCow-parsnip needs full sun or very light shade in moist but well-drained soil of moderate fertility. Fertilize monthly during the growing season. Remove old flower stalks.
PropagationSow seeds where they are to grow in the garden as soon as they are ripe. Perennials can be divided in spring or summer.
ProblemsLeaf spots, stem rot.