Growing Yarrow 'Coronation Gold' in a pot

Once established, Achillea 'Coronation Gold' is exceptionally low-maintenance and drought-tolerant, requiring little watering even in dry summers. Water newly planted specimens regularly for the first season, but mature plants rarely need supplementary irrigation except during prolonged drought. Overwatering or planting in moisture-retentive soil encourages weak, floppy growth and increases the risk of root rot and mildew. Feed sparingly. In April or May, apply a light dressing of general-purpose granular fertiliser or a handful of blood, fish, and bone around the base of the plant. Avoid high-nitrogen feeds, which promote lush foliage at the expense of flowers and make stems more likely to flop. On poor, free-draining soils, a single spring feed is sufficient; on richer ground, feeding may not be necessary at all. Achillea 'Coronation Gold' is fully hardy to zone 3 and requires no winter protection in temperate Europe. The plant dies back to a basal rosette of foliage in autumn, and the crown will overwinter without issue in well-drained soil. Avoid mulching the crown with organic matter in winter, as this can trap moisture and cause rot. Powdery mildew is the most common problem, particularly in humid conditions or where air circulation is poor. Ensure adequate spacing and avoid overhead watering. Aphids occasionally cluster on young shoots and flowerheads in spring; a strong jet of water or insecticidal soap usually resolves the issue. Slugs and snails rarely bother established plants but may nibble emerging shoots in early spring.