Common Names: yarrow, milfoil
Type: Herbaceous perennial
Size: 18 to 30 in. high and wide; flower stems to 3 ft.
Flowers: White flowers in flat clusters, late spring to early fall; finely divided medium green leaves 6 to 8 in. long. Many other colors available.
Uses: Slopes, cut flowers, ground cover, rock garden, some salt tolerance. Tolerates heat. Fire resistive.
Wildlife: Nectar and seeds. Butterfly pollinated. Butterfly larvae. Deer resistant. Rabbit resistant.
Soil: Adapts to sand, clay, or calcareous soil.
Water: None to low water once established. Develops tap root.
Sun: Full sun to some shade.
Pruning: Prune (deadhead) dead flowers back to branching stems. Prune central stems as they die back. Cut plant to 6 in. in spring before new buds form.
Pests & Diseases: Stem rot, powdery mildew, gray mold (Botrytis).
Notes: Approximately 100 species of Achillea exist. A. millefolium spreads by underground runners; needs dividing periodically. Appears along roadsides. Many colorful cultivars are available. Hardy to -30° F.