Hemp-agrimony
Eupatorium cannabinum · Asteraceae
The gardener's calendar
Ideal time to plant hemp-agrimony: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Foliage
- Deciduous
- Flowering
- July to September
- Adult size
- 80 to 150 cm in height
- Growth
- Fast
- Hardiness
- Very hardy (down to -15°C)
- Origin
- Europe, Western Asia
- Soil type
- Moist, fresh, rich in organic matter
Care
Watering
Hemp agrimony appreciates constantly moist soil, particularly during growth and flowering periods. Water regularly during prolonged dry spells, except in winter when water needs decrease. It tolerates wet areas and poorly drained soils well.
Exposure
Place hemp agrimony in full sun or partial shade for optimal flowering. It accepts partial shade but flowers more generously with 4 to 6 hours of direct sunlight daily. It's perfectly suited to partially shaded areas of natural gardens.
Soil
Prepare rich, fertile and moist soil, enriched with compost or peat. Hemp agrimony adapts to different soil types as long as they remain fresh. It's ideal for pond edges, wet areas or poorly drained slopes.
Pruning and cutting
Cut back the plant in late autumn or early winter, to 10-15 cm from the ground, after fruiting. You can also pinch it lightly in summer to encourage a more compact shape. Remove faded flowers to encourage prolonged flowering.
Fertilizer
An application of well-decomposed compost in spring is generally sufficient for this undemanding plant. In poor soil, a balanced organic fertilizer can be applied at the start of the growing season. Avoid excess nitrogen which would promote foliage at the expense of flowering.
Diseases and pests
Hemp agrimony is generally robust and rarely susceptible to diseases under appropriate conditions. Watch for powdery mildew in cases of stagnant moisture or poor air circulation. Excess humidity can promote root rot: ensure proper drainage.
Did you know?
Hemp agrimony owes its genus name "Eupatorium" to Eupator Mithridate VI, King of Pontus in the 1st century BC, who is said to have used the plant for medicinal purposes. Its epithet "cannabinum" evokes its palmate leaves resembling those of hemp, although the two plants are not botanically related.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
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Tips generated and checked by Viridia — adapt them to your local climate.