Persicaria milletii
crimson knotweed
P. milletii is a clump-forming, upright, semi-evergreen perennial with linear to lance-shaped, pointed, dark green leaves to 30cm long with prominent mid-ribs. Profuse, dense, cylindrical spikes of slender, rich-crimson flowers from early summer to late autumn to 60cm tall
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Size
Ultimate height
0.5–1 metresTime to ultimate height
2–5 yearsUltimate spread
0.1–0.5 metresGrowing conditions
Moisture
Moist but well–drained, Poorly–drainedpH
Acid, Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Green | |||
|---|---|---|---|---|
| Summer | Red | Green | ||
| Autumn | Red | Bronze | ||
| Winter | Brown |
Position
- Full sun
- Partial shade
Aspect
South–facing or North–facing or East–facing or West–facing
Exposure
Exposed or Sheltered Hardiness
H3Botanical details
- Family
- Polygonaceae
- Native to the UK
- No
- Foliage
- Semi evergreen
- Habit
- Bushy
- Genus
A genus of herbaceous, rhizomatous perennials with erect, unbranched stems, bearing short terminal spikes of small, white or pink, bell-shaped flowers
- Name status
Correct
- Plant range
- Himalaya to C China
How to grow
Cultivation
Grow in any moist soil in full sun or partial shade. Tough and non-invasive but may self-seed
Propagation
Propagate by division in spring or autumn
Suggested planting locations and garden types
- City and courtyard gardens
- Gravel garden
- Cottage and informal garden
- Wildflower meadow
- Flower borders and beds
Pruning
Cut back after flowering
Pests
Generally pest-free
Diseases
Generally disease-free
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