9 cm sized pot.  Achillea ageratum Moonwalker is a hardy perennial with strong smelling foliage.  Bright yellow clusters consisting of many tiny ball shaped flowers are on show from summer into autumn and are loved by bees and beneficial insects.  Reaches 40-50cm high.  Looks great planted with a mix of other yellow flowering perennials (daylilies, coreopsis, helenium), red achillea and hot coloured dahlias.