Few plants announce summer quite like a red hot poker. Its tall spikes of tubular flowers open from the bottom up, often starting red and fading to yellow, so each torch glows in two colours at once. Bumblebees work them all day and they keep coming from early summer into autumn if you choose a few varieties.
Kniphofia comes from the grasslands and mountain slopes of southern Africa, and that origin explains most of what it needs. This guide covers where to plant it, how deep to set the crown, how to water and feed, the winter routine that prevents rot, dividing old clumps and the best border partners.
Kniphofia, red hot poker at a glance
- Botanical name Kniphofia (species and hybrids, formerly also listed as Tritoma)
- Common name Red hot poker, torch lily
- Plant type Clump-forming herbaceous perennial, evergreen or deciduous depending on variety
- Hardiness Most are RHS H5 (hardy to about -10 to -15C) in well-drained soil, a few smaller types are slightly less hardy
- Height and spread Varies with variety, from about 50cm for dwarf forms to 1.5m for tall ones, spreading 45cm to 1m
- Flowering June to October depending on variety, in red, orange, yellow, cream and lime green, often two-toned as buds open
- Foliage Long, arching, grass-like leaves, mid to grey-green
- Position Full sun, open and airy
- Soil Fertile but well-drained, sandy or loamy, improve heavy clay with grit
- Good for Gravel gardens, coastal gardens, hot borders, pollinators and cut flowers
Sun, space and drainage
Pokers flower best in full sun with plenty of air around them. In shade they produce lots of leaves and very few spikes, and crowded clumps hidden among taller plants tend to sulk.
Good drainage matters as much as light. They are a fine choice for gravel gardens, sunny banks and seaside gardens, where they shrug off wind and salt. Allow at least 60cm between plants for taller varieties, as a mature clump can reach a metre across.
Planting a poker the right way
Spring is the ideal time to plant, giving roots a full season to establish before their first winter. Autumn planting works on light soils but carries more risk on heavy ground.
- Dig a hole twice the width of the pot and loosen the soil at the base.
- On clay, mix a couple of spadefuls of grit or gravel into the planting hole and the surrounding soil.
- Set the plant so the crown sits at the same level it was in the pot, never deeper.
- Firm in gently and water well, then keep watering weekly through the first summer in dry spells.
Watering and feeding through the year
In the wild, pokers get most of their rain in summer and stay dry in winter. Established clumps are drought-tolerant and will cope with a dry Lincolnshire summer, but a deep soak during a long drought in June or July gives you more and bigger spikes.
Feed lightly in spring with a general fertiliser or a mulch of garden compost around, not over, the crown. Too much nitrogen gives lush leaves at the expense of flowers. Our guide to the best drought-tolerant plants for UK gardens has more on growing plants that ask for little watering.
Deadheading and spring tidying
Cut each spent flower stem right down to the base once it has faded. This keeps the clump neat and can encourage a second flush on repeat-flowering varieties.
Leave the foliage alone in autumn. On evergreen types, simply pull away dead and tatty leaves in April. On deciduous types, cut the old brown leaves back to a few centimetres above the crown in early spring as new growth starts.
Bringing pokers through a wet winter
Cold alone rarely kills a red hot poker. Water sitting in the crown and freezing is what causes rot. The simple fix is to gather the leaves of evergreen types in late autumn and tie them loosely into a wigwam over the centre of the plant with soft twine, so rain runs off the outside.
For deciduous varieties and young plants in their first winter, a mulch of dry bark or straw around the crown gives extra insulation. Remove the ties and mulch in spring once hard frosts have passed.
Dividing congested clumps
After four or five years a clump can become crowded and flower less in the middle. Lift it in late spring, just as new growth begins, and split it into sections with a sharp spade, making sure each piece has healthy roots and several shoots.
Replant the divisions straight away at the same depth and water them in. Expect a year without many flowers while they settle. Plants raised from seed vary a lot and can take three years to bloom, so division is the reliable way to keep a favourite variety.
When pokers refuse to flower or start to rot
A clump with no spikes is usually too young, too shaded, recently divided or growing in very rich soil. Moving it into full sun and leaving it undisturbed normally solves the problem within a season.
Soft, brown, smelly crowns in spring point to winter wet, so improve drainage before replanting healthy pieces. Slugs and snails sometimes graze emerging shoots, and thrips can mottle leaves in hot summers, but pokers are otherwise trouble-free. They are not commonly listed as poisonous to people or pets.
Pairing pokers in borders and gravel
Pokers look their best rising through softer, airier plants that frame the bold spikes. Grasses are a natural partner, and in a hot border the fiery colours sit well with blues and purples.
Try them with Stipa gigantea, Verbena bonariensis, Eryngium, Salvia and Crocosmia. Lime and cream varieties pair beautifully with dark-leaved plants, and a group of three of one variety reads better from a distance than a scatter of mixed colours.
Questions about Kniphofia, red hot poker
Should I cut back red hot pokers in autumn?
No, leave the leaves on over winter because they protect the crown. Cut flower stems down once faded, then tidy dead foliage in spring. Evergreen types benefit from having their leaves tied up over the crown in late autumn.
Why is my red hot poker not flowering?
The most common reasons are shade, soil that is too rich, a plant that is still young or a clump that was recently divided or moved. Pokers need full sun and can take a year or two to settle. Avoid high-nitrogen feeds, which favour leaves over spikes.
Do red hot pokers attract bees?
Yes, bumblebees love the tubular, nectar-rich flowers and visit them all through the summer. In their native South Africa they are pollinated mainly by sunbirds. A long succession of varieties gives bees a food source from June into autumn.
Are red hot pokers invasive?
No, they form slowly expanding clumps and do not spread by runners or seed aggressively in UK gardens. A clump grows wider over several years and can be divided when it gets too large. Seedlings occasionally appear but are easy to remove.
If you are planning a sunny border with real height and colour, take a look at our perennials collection for red hot pokers and plants to grow alongside them.