This Ageratum ,which is native to Mexico and tropical America, is a perennial in warm climates or spring/summer annual in cold climates. Here it produces pale blue fluffy flowers for most of the year .It likes damp semi shaded places but will also grow in full sun. The common names given to it are unusual .It gets called 'Billy-goat stink weed' because the leaves have an unpleasant smell and it has become weedy in warm coastal areas of the north coast. .It also goes by the name of floss flower and the curious title of 'wet-the-bed'. Seedlings are usually sold of the dwarf varieties such as 'Blue Mink' and colour forms of white or pink are available.