Yarrow (Achillea millefolium) is a widely distributed native plant with so much going for it. It is drought tolerant, the fresh and dried foliage has a pleasant fragrance, it is a popular nectar source for butterflies and is the host plant of many native moths and beetles. Yarrow spreads via rhizomes and will proliferate readily in the garden. Note, seeds are very small.
Yarrow has a unique and often confusing history. In terms of its range in North America, it is both native and introduced. Native A. millefolium populations existed in North America prior to European colonization, however additional stock of the plant was brought over by settlers from Europe and Asia. The introduced plants were of the same species, but did exhibit some genetic differences and hybridized with native stands.
No pre-treatment required. Sow seed at soil surface. Do not let seedling dry out while establishing.