Eupatorium cannabinum
Hemp agrimony
Common names: Holy rope
At a glance
- Light
- Partial shade
- Lifespan
- Perennial
- Flowering
- Jul–Sep
- Hardiness
- Hardy
- Origin
- Native to Germany
Photo: Burkhard Mücke · CC BY-SA 4.0 · Source
Description
Hemp agrimony (Eupatorium cannabinum) is a native perennial that can reach up to 1.5 m in damp habitats. From July to September it produces large, pinkish flower heads that attract butterflies and other insects. The species name refers to its hemp‑like leaf shape; it is not related to true hemp. Historically it was used in herbal medicine, but today its ecological value is emphasized. The plant is toxic, consumption of any part can be harmful.
Care instructions
Choose a moist to wet site in full sun or partial shade, such as a pond edge or near a rain barrel. The soil may be heavy and fertile; the plant tolerates waterlogging better than drought. Water regularly during hot summer weeks, especially when young. Prune stems low to the ground in late winter (late February to early March) to encourage vigorous spring regrowth. Leave spent flower heads into autumn; they provide seed and winter habitat for birds and insects.
The care notes were machine-translated from German.
Garden year
FloweringJul–Sep
Soil & site
Soil pH
Soil type
moist, nutrient-rich, humus-rich, loamy
Hemp-agrimony comes from riverbanks and wet meadows and accordingly wants it moist to wet. A humus-rich, nutrient-rich loam soil with good water retention suits it best; the plant tolerates waterlogged spots at the edge of a pond without problems. On dry, sandy soil it stays much smaller and flowers more weakly.
Feeding
Medium feeder
Months
Apr, Jun
A trowelful of compost in early spring around the root area is usually enough as a starting supply. If you want to encourage abundant flowers for butterflies and bees, add another portion of well-rotted manure or compost at the beginning of June. A mulch of leaves or grass clippings keeps moisture in the soil and releases nutrients as a bonus.
Overwintering
Hemp-agrimony is hardy in Central Europe and needs no special protection. It is best to leave the stems standing over winter: they offer insects a winter refuge and give the plant some frost protection at the base. Only in early spring, shortly before the new growth comes, cut the old stems back close to the ground.
Propagation
Methods
- From seed
- Division
- Cuttings
The easiest way is to divide established clumps with a spade in spring or autumn and set the pieces directly in their new place. Sowing works as a cold-stratification seed outdoors in autumn, or from spring after a cold phase in the fridge; the seeds need light to germinate and are only pressed down rather than covered. Tip cuttings in early summer also root reliably if you keep them moist and shaded. Self-seeding is quite generous in moist locations anyway, and young seedlings are easy to transplant.
Companion planting
Companion planting is partly traditional gardening lore. Where the reason is known, it is given.
Some of these explanations were machine-translated.
For your garden
Grow Hemp agrimony yourself
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