How to grow yarrow
Overview
Yarrow (Achillea millefolium) is a hardy, clump-forming perennial grown for its flat-topped flower clusters and finely divided, aromatic foliage. It thrives in poor, well-drained soils and full sun, making it an essential plant for low-maintenance and dry gardens.
Varieties
- Achillea millefolium 'Cerise Queen' — Deep cerise-pink flowers, very drought-tolerant, popular in Australian cottage gardens.
- Achillea millefolium 'Moonshine' — Sulphur-yellow flowers with grey-green foliage, excellent for cutting and borders.
- Achillea millefolium 'Paprika' — Vibrant red-orange flowers fading to cream, a standout in dry gardens.
Soil Preparation
Yarrow prefers neutral to slightly alkaline soils (pH 6.5–7.5) with sharp drainage. It thrives in poor, rocky, or sandy soils; avoid rich, moisture-retentive ground. No need for heavy amendment—add a little lime if soil is very acidic.
Growing Guide
Plant yarrow in full sun with excellent drainage; it tolerates poor, sandy, or gravelly soils. Space plants 30–45 cm apart. Water sparingly once established—overwatering causes floppy growth. Cut back hard after the first flush to encourage a second bloom and keep plants compact. Divide every 2–3 years in early spring to maintain vigour.
Sowing
Sow yarrow seed directly in autumn or spring, barely covering with soil (1–2 mm deep). Germination takes 10–14 days at 15–20°C. Thin to 30 cm apart. For best results, start in punnets and transplant after frost risk passes.
Care
Feed yarrow lightly in spring with a balanced slow-release fertiliser. Cut back spent flower stems to the base after flowering to encourage a second flush and maintain compact shape. Divide clumps every 2–3 years in early spring to keep plants vigorous.
Companion Planting
Yarrow pairs beautifully with roses, lavender, and ornamental grasses, where its flat flower heads contrast with spiky forms. Avoid planting near moisture-loving vegetables like lettuce or celery, as yarrow's dry conditions may conflict.
Common Pests & Risks
Aphids may cluster on new growth; blast off with water or use a mild soap spray. Powdery mildew appears in humid or crowded conditions—ensure good air circulation and avoid overhead watering. Root rot can occur in heavy, wet soils.
Harvesting
Harvest yarrow flowers when the heads are fully open but before they begin to fade, cutting stems at the base. For dried arrangements, hang bunches upside down in a dark, airy space. Flowers can also be harvested for fresh bouquets throughout summer.
Troubleshooting
Yellow leaves: overwatering or poor drainage—reduce watering and improve soil. Floppy stems: too much shade or rich soil—move to full sun and cut back. Powdery mildew: humid, crowded conditions—space plants and avoid overhead watering. No flowers: excessive nitrogen or too much shade—cut back on feed and ensure full sun. Brown leaf edges: salt buildup or drought stress—flush soil and water deeply.