Large mustard-gold flower plates give Achillea Coronation Gold a bold, level layer of color above fine silver-green foliage. The upright perennial reaches about 2.5 to 3 feet tall and spreads roughly 1.5 to 2 feet. Its strong stems work well through the middle of a sunny garden bed and provide useful flowers for cutting.
Full sun supports sturdy growth and the richest yellow color. Water regularly during establishment, then let the soil dry between soakings. Heavy feeding is unnecessary and can weaken the stems, so use only a thin spring compost layer on poor soil.
Deadhead faded flower heads during summer when a longer display is wanted. Cut back untidy foliage in spring before new shoots expand. Established clumps can be divided in spring and replanted in well-drained soil. Aphids may gather on soft growth, while open spacing and soil-level watering help reduce powdery mildew.