Although there are now several varieties of yarrow that are more "refined"--shorter, brighter colors, bushier growth--this rangy, near-wild beauty is still one of my favorites. About 5 feet tall and regal, it tolerates poor soil (but prefers rich, well-drained loam) and little water and still keeps blooming. Yarrow's flower clusters and delicate foliage complement any fresh bouquet; better yet, the flowers retain their color and texture when dried, making yarrow an important part of dried-flower arrangements.
Yarrow is disease- and pest-free and very hardy. The soft, fern-like leaves have a distinctive odor that I find very pleasant, but many people, on first whiffing yarrow, pucker up their faces and say something like "Eeeuuww!" The somewhat flattened flower clusters grow at the ends of incongruously long stems that occasionally topple over. Because most of the foliage clusters at the base of the plant, the stems can look quite bare at times; yarrow will be more attractive in the garden when grown behind lower, bushier plants.
According to Rodale's Encyclopedia of Herbs, yarrow is an ancient plant, known to European cave dwellers 60,000 years ago. The Chinese used yarrow stalks to cast the I Ching, and yarrow was present during the Trojan War: Achilles used it to treat his comrades'wounds, which may explain the plant's botanical name. Even the American Indians used yarrow as medicine, applying it to sores and injuries. Sure enough, modern scientists have discovered that yarrow contains an alkaloid that helps hasten blood clotting, and a volatile oil with anti-inflammatory effects.