Overview
Koenigia weyrichii is a clump forming herbaceous perennial in the genus Koenigia, part of the Polygonaceae family, with semi evergreen foliage. Koenigia weyrichii grows best in full sun and partial shade, and tolerates clay and loam soils and any pH. Its UK hardiness is rated H6. Suggested uses include city and courtyard gardens, cottage and informal garden, prairie planting, rock garden and gravel garden.
About
Koenigia weyrichii (synonym Persicaria weyrichii), the Chinese knotweed or Weyrich's knotweed, is a large, perennial, rhizomatous herb native to northeastern Asia in Kamchatka, Sakhalin, and northern and central Japan. It is also locally naturalised in northern Europe. It is one of the parents of the cultivated hybrid Koenigia × fennica, the other being Koenigia alpina. In the garden it prefers full sun and partial shade and clay and loam soil. In UK gardens it is very hardy across most of the UK (RHS H6). Suggested uses include city and courtyard gardens, cottage and informal garden, prairie planting, rock garden and gravel garden. It tolerates soil of any pH, moist but well-drained, poorly-drained conditions and north-facing, west-facing, east-facing and south-facing aspects.
Wikipedia contributors, CC BY-SA 4.0 — Koenigia weyrichii
Growing conditions
Best soil and position for Koenigia
- Sunlight
- Full sun, Partial shade
- Soil type
- Clay, Loam
- Soil pH
- Acid, Alkaline, Neutral
- Soil moisture
- Moist but well-drained, Poorly-drained
- Aspect
- North-facing, West-facing, East-facing, South-facing
- Exposure
- Exposed, Sheltered
- UK hardiness
- H6
Plant details
Koenigia weyrichii size, habit and characteristics
- Plant type
- Herbaceous Perennial
- Habit
- Clump forming
- Foliage
- Semi evergreen
- Suggested uses
- City and courtyard gardens, Cottage and informal garden, Prairie planting, Rock garden, Gravel garden
Care notes
Pruning and caring for Koenigia weyrichii
- Propagation
- Propagate by division in spring or autumn or propagate by seed in spring
- Pest resistance
- Generally pest-free
- Disease resistance
- Generally disease-free
Frequently asked questions
Where is the best place to plant Koenigia weyrichii?
Koenigia weyrichii prefers full sun and partial shade. It suits exposed and sheltered positions.
What soil does Koenigia weyrichii need?
Koenigia weyrichii grows best in clay and loam soil. It is happy in soil of any pH. Aim for soil that stays moist but well-drained to poorly-drained.
Is Koenigia weyrichii hardy in the UK?
Koenigia weyrichii has an RHS hardiness rating of H6, meaning it is very hardy, tolerating -20 to -15°C across most of the UK.
How do I propagate Koenigia weyrichii?
Propagate by division in spring or autumn or propagate by seed in spring.