Overview
Kniphofia triangularis is a clump-forming, upright perennial in the genus Kniphofia, part of the Asphodelaceae family, with evergreen or deciduous; narrow, arching, strap-shaped or grassy foliage. Kniphofia triangularis grows best in full sun, and tolerates fertile sandy or loamy soil soils and neutral to slightly acid pH. Its UK hardiness is rated H4–H6. Suggested uses include borders, rock gardens, containers and and as a striking architectural plant in sunny garden spots.. It is native to S Africa.
About
Kniphofia triangularis is a clump-forming, upright perennial from South Africa grown for its summer flowering. It carries narrow, arching, strap-shaped or grassy leaves that may be evergreen or deciduous. Flowering occurs from June to September. Best sited in a sunny, south- or west-facing position in fertile sandy or loamy soil that stays moist in summer but drains in winter.
About the genus
Kniphofia is a genus of perennial flowering plants in the family Asphodelaceae, first described as a genus in 1794. All species of Kniphofia are native to Africa. Common names include tritoma, red hot poker, torch lily and poker plant.
Wikipedia contributors, "Kniphofia", CC BY-SA 4.0 — Kniphofia
In the garden
Kniphofia triangularis is a clump-forming, upright perennial native to South Africa, cultivated for its summer display of flowers that appear from June to September. The foliage is narrow and arching, sometimes remaining evergreen or dying back depending on the season and site. Plant in full sun on fertile sandy or loamy soil with a neutral to slightly acid pH; the soil should hold moisture through the summer months yet shed excess water over winter. Place plants in a south- or west-facing spot where they receive strong light; they tolerate both exposed and sheltered situations. Hardiness is H4–H6 (average to very hardy) and USDA zones 5–9, so plants will cope across most UK gardens provided winter drainage is good. Avoid waterlogged winter conditions on heavy soils by choosing a raised bed or improving drainage with grit or sharp sand in the planting area. Use Kniphofia triangularis in sunny mixed borders, on gravel or rock garden margins, or in large containers where its upright habit provides architectural form. It adapts to both sheltered and more exposed positions and suits schemes that accept either persistent narrow foliage or a seasonal die-back of leaves.
Growing conditions
Best soil and position for Kniphofia
- Sunlight
- Full sun
- Soil type
- Fertile sandy or loamy soil
- Soil pH
- Neutral to slightly acid
- Soil moisture
- Moisture-retentive in summer, well drained in winter
- Aspect
- South or west facing
- Exposure
- Exposed or sheltered
- UK hardiness
- H4–H6
Plant details
Kniphofia triangularis size, habit and characteristics
- Plant type
- Perennial
- Habit
- Clump-forming, upright
- Foliage
- Evergreen or deciduous; narrow, arching, strap-shaped or grassy
- Suggested uses
- Borders, rock gardens, containers, and as a striking architectural plant in sunny garden spots.
- Native to
- S Africa
Care notes
Pruning and caring for Kniphofia triangularis
- Cultivation
- What most red hot pokers want is summer moisture combined with winter dryness. Plant on a free-draining site, water generously while the spikes are forming, then protect the crowns of less hardy kinds with a dry mulch or by tying the leaves up over the centre in autumn.
- Pruning
- Remove faded spikes at the base. Cut deciduous foliage down in late autumn; on evergreens pull away dead leaves by hand rather than shearing the whole clump.
- Propagation
- Divide established clumps in late spring — autumn division risks rotting. Species germinate readily from seed but take two to three years to flower.
- Pest resistance
- Usually undemanding, but aphids, thrips, slugs and snails can all take advantage of the crown and new growth.
- Disease resistance
- Healthy in suitable conditions. Crown and root rot follow winter waterlogging.
Frequently asked questions
How do I grow Kniphofia triangularis?
What most red hot pokers want is summer moisture combined with winter dryness. Plant on a free-draining site, water generously while the spikes are forming, then protect the crowns of less hardy kinds with a dry mulch or by tying the leaves up over the centre in autumn.
Where is the best place to plant Kniphofia triangularis?
Kniphofia triangularis prefers full sun. It suits exposed or sheltered positions.
What soil does Kniphofia triangularis need?
Kniphofia triangularis grows best in fertile sandy or loamy soil soil. It prefers neutral to slightly acid soil. Aim for soil that stays moisture-retentive in summer to well drained in winter.
How do I prune Kniphofia triangularis?
Remove faded spikes at the base. Cut deciduous foliage down in late autumn; on evergreens pull away dead leaves by hand rather than shearing the whole clump.
Is Kniphofia triangularis hardy in the UK?
Kniphofia triangularis has an RHS hardiness rating of H4, meaning it is hardy through an average UK winter, tolerating -10 to -5°C.
How do I propagate Kniphofia triangularis?
Divide established clumps in late spring — autumn division risks rotting. Species germinate readily from seed but take two to three years to flower.
More in the Kniphofia genus
- Kniphofia 'Royal Standard'red-hot poker 'Royal Standard'
- Kniphofia gracilisRed Hot Poker
- Kniphofia rufaRed Hot Poker
- Kniphofia tuckii of gardensRed Hot Poker
- Kniphofia 'Ada'red-hot poker 'Ada'
- Kniphofia 'Erecta'red-hot poker 'Erecta'
- Kniphofia 'Goldelse'red-hot poker 'Goldelse'
- Kniphofia 'Goldfinch'Red Hot Poker