The Yarrows are among the best perennials for planting in hot, dry and sunny locations, providing good colour throughout the summer months. This dwarf species forms a tight mat of fuzzy olive-green leaves, topped by clusters of bright canary-yellow flowers in early summer. Best in a well-drained rock garden. Clumps are easily divided in early spring or fall. Trim off faded flower heads to tidy up the plants. Evergreen.