Caring for Hemp Agrimony

Hemp agrimony has high water needs and performs best when the soil remains consistently moist throughout the growing season. Water regularly from spring through to autumn, particularly during dry spells; plants in sunnier positions or free-draining soils may need watering two or three times a week in summer. Mulch annually in spring with garden compost or leaf mould to help retain moisture and suppress weeds around the base. Feed once a year in March with a general-purpose granular fertiliser or a generous top-dressing of well-rotted manure or compost. This supports the tall, leafy growth and abundant flowering that follows in summer and autumn. Avoid high-nitrogen feeds later in the season, as soft late growth is more vulnerable to winter damage. Hardy to zone 3a, hemp agrimony needs no winter protection in temperate Europe. The top growth dies back completely, and the roots overwinter dormant in the soil. Leave the dead stems standing until March; they provide habitat for beneficial insects and food for seed-eating birds. Pests are rarely a problem. Aphids occasionally colonise the soft shoot tips in spring, but these seldom cause lasting harm and attract ladybirds and hoverflies. Powdery mildew can appear on the foliage in late summer, especially in dry conditions or where air circulation is poor; ensure adequate watering and avoid overcrowding to minimise risk. If mildew does develop, it's largely cosmetic and won't significantly affect the plant's health. Hemp agrimony is a magnet for pollinators—butterflies, bees, and hoverflies visit the pink flower clusters in droves from July through September, making it an excellent choice for wildlife-friendly gardens.