White Yarrow as finely divided, fern-like leaves and a pungent scent. Â Flowers are white and occur in flat-topped flower clusters. This species has rhizomes and can spread aggressively in home gardens or where soils are moist. Â It is best used in dry areas where soil stabilization is needed, or as an aggressive ground cover to help choke out weeds. H90cm. P. Sun. S. 6000seeds/ gm Perennial - Plant in: Full Sun. S. 6000seeds/ gm