Yarrow (Achillea millefolium) is a low-growing perennial ground cover with delicate fernlike leaves and yellow-tinged white flowers on 2- to 3-foot stalks that bloom from July through October. The plant’s blossoms make it a bit top-heavy, so it should be protected from the wind. It will perform well in poor soils with good drainage and can be an aggressive plant spreading by rhizomes. Division should be completed every few years. It is deer and rabbit-resistant.