Alternanthera dentata 'Purple Knight'
A vigorous, spreading upright tender evergreen perennial grown as an annual for the dark purple stems and foliage. Leaves are lance shaped and flowers are occasional, white and insignificant, in summer.
Size
Ultimate height
0.1–0.5 metresTime to ultimate height
1–2 yearsUltimate spread
0.1–0.5 metresGrowing conditions
Moisture
Moist but well–drained, Well–drainedpH
Acid, Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Purple | Purple | ||
|---|---|---|---|---|
| Summer | Purple | White | Purple | |
| Autumn | Purple | Purple | ||
| Winter | Purple | Purple |
Position
- Full sun
Aspect
South–facing
Exposure
Sheltered Hardiness
H1CBotanical details
- Family
- Amaranthaceae
- Native to the UK
- No
- Foliage
- Evergreen
- Habit
- Bushy, Spreading branched, Columnar upright
- Genus
Alternathera are bushy annuals and perennials with colourful leaves and insignificant flowers
- Name status
Accepted
How to grow
Cultivation
Plant in light moist but well-drained fertile soil in sheltered sunny sites as an annual. Darkest leaf colur develops in full sun. Also grown under glass in light loam compost with plenty of light, water and regular feeding.
Propagation
Propagate by division, seed and stem tip cuttings
Suggested planting locations and garden types
- City and courtyard gardens
- Patio and container plants
- Flower borders and beds
- Ground cover
- Garden edging
Pruning
Pinch out tips and clip back to keep bushy shape
Pests
May be susceptible to glasshouse red spider mite
Diseases
May be susceptible to fusarium wilt
Get involved
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