Verbena officinalis, the common vervain or common verbena, is a perennial herb native to Europe. It grows up to a metre/yard high, with an upright habitus. The lobed leaves are toothed, the delicate spikes hold mauve flowers.
Growth: average in spring, summer, autumn; in rockery, the speed of growth of Agave macroacantha depends on the presence of fertilizers and a good watering during planting.