If seen in an area of grass that is kept short all year round, Yarrow is a good indicator of previous meadows that have been mown down. Does not seem to tolerate grazing, but tolerates trampling well. Native to most of the northern hemisphere. Spreads by rhizomes. Very drought resistant, often appearing green when all plants are shriviled up and brown. The white and sometimes pink flowers are very attractive to butterflies. May, june and july are the flowering months of this perrenial, although it commonly flowers right up to the end of august.