Caring for Fernleaf yarrow

Once established, goudduizendblad is exceptionally low-maintenance and drought-tolerant. Water only during prolonged dry spells in the first growing season to help roots establish; thereafter, natural rainfall is usually sufficient. Overwatering or poorly drained soil can lead to root rot and weak, floppy growth, so err on the side of dryness. Feed sparingly. In April or May, apply a light dressing of general-purpose granular fertiliser (such as blood, fish and bone) or a balanced slow-release feed around the base of the plant. Avoid high-nitrogen fertilisers, which promote lush foliage at the expense of flowers and can cause stems to flop. On fertile soils, feeding may not be necessary at all—goudduizendblad is adapted to lean conditions and excessive fertility weakens it. This perennial is fully hardy to zone 3, so overwintering in temperate Europe presents no difficulty. Leave the crown undisturbed through winter; it will reshoot reliably in spring. No protective mulch or covering is needed. Goudduizendblad is generally pest- and disease-free, but watch for powdery mildew in late summer, especially in crowded plantings or during humid weather. Improve air circulation by thinning congested clumps and avoid overhead watering. Aphids occasionally cluster on young shoots in spring; a strong jet of water or an insecticidal soap usually resolves the problem. Slugs and snails rarely bother the tough, aromatic foliage. Mulch lightly with gravel if desired to suppress weeds, but keep mulch clear of the crown to prevent rot.