How to grow agrimony
Overview
Agrimony is a herbaceous perennial grown for its spikes of yellow flowers and finely cut foliage, adding vertical interest to cottage gardens. It is also valued for its traditional medicinal uses. Requires full sun and well-drained soil to thrive.
Soil Preparation
Agrimony thrives in well-drained, sandy loam with a pH between 6.0 and 7.0. Enrich poor soils with compost before planting. Avoid heavy clay or waterlogged sites to prevent root rot.
Growing Guide
Sow seeds directly into well-prepared soil after the last frost, or start indoors in spring. Space plants 30–40 cm apart for good air circulation. Agrimony prefers full sun and moderate moisture; once established it is fairly drought tolerant. Cut back after flowering to control self-seeding and maintain a tidy habit.
Sowing
Sow seeds on the surface of moist seed mix, barely covering them; germination takes 14–21 days at 18–21°C. Direct sow in spring once soil warms, or start indoors 6 weeks before last frost. Thin seedlings to 30 cm apart.
Care
Apply a balanced slow-release fertiliser in early spring as new growth appears. Deadhead spent flower stalks to encourage a second flush of blooms. Divide clumps every 3–4 years to maintain vigour and prevent woody centres.
Companion Planting
Plant with other sun-loving herbs such as lavender, sage, and thyme. Agrimony also pairs well with echinacea and catmint for a pollinator-friendly bed. Avoid planting near moisture-loving plants like mint, as agrimony prefers drier conditions.
Common Pests & Risks
Aphids may occasionally infest new growth; spray with a strong jet of water or apply insecticidal soap. Powdery mildew can appear in humid conditions; ensure good spacing and air circulation. Root rot is possible if soil is waterlogged.
Harvesting
Harvest flowering tops when the spikes are fully open, on a dry morning. Cut stems and hang upside down in a shady, airy spot for drying. Leaves can be picked before flowering for use in herbal teas.
Troubleshooting
Yellow leaves with sticky residue: aphid infestation; hose off or use insecticidal soap. White powdery coating on leaves: powdery mildew; improve airflow and avoid overhead watering. Sudden wilting despite moist soil: root rot; check drainage and reduce watering. Few flowers in shade: move to full sun. Stems flopping over: may need support in rich soil.