PL. —Kniphofia uvariaBotanical illustration — drop image
Kniphofia uvaria

Red Hot Poker

SummerFall
5b9bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Peak bloom
Summer
Peak bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Kniphofia uvaria, the red hot poker or torch lily, is a South African clump-forming perennial grown for its bold, bicolor flower spikes — dense torches of coral-red buds opening to yellow-orange from the base up, held well above a fountain of grassy, blue-green foliage. It is one of the most reliable hummingbird plants in the summer border and reads as a strong vertical accent among softer, mounding perennials.

It wants full sun and, above all, drainage: soggy winter soil around the crown is the most common way to lose a plant, far more so than cold. In its hardiness range it is otherwise low-maintenance and long-lived, resents being divided too often, and is largely ignored by deer and rabbits. Where marginal, gardeners tie the strappy leaves up over the crown before winter to shed water and add a loose mulch, rather than cutting the foliage away.

Care guide
SunFull sun
WaterModerate; drought tolerant once established
SoilWell-drained, average to sandy; poorly drained soil rots the crown
Spacing18–24 inches
Height2–4 feet
Zone5b – 9b
Frost hardy
Seasonal tasks
spring
watchNew grassy foliage flushes fast in spring; work in a light topdressing of compost rather than a heavy feed, which produces floppy growth at the expense of flower spikes.
watchLeave clumps undisturbed; Kniphofia resents frequent division and flowers best left undivided for 4–5 years.
watchIn zones 5b–6b, tie the strappy leaves up into a loose knot over the crown after the first hard frost to shed winter wet, then mulch lightly — do not cut the foliage away.
sowPlant potted divisions in spring once the soil has warmed, siting the crown slightly proud of grade in a well-drained spot — wet winter soil around the crown is the main way this plant is lost.
summer
cutCut spent flower spikes at the base once the last florets fade to tidy the clump and redirect energy; established plants often push a lighter second flush.
watchCheck for thrips distorting new spikes during hot, dry stretches; a strong water spray usually knocks populations back.
Common problems

Root rot

Symptoms

Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.

Treatment

Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.

Crown Rot

Symptoms

Lower leaves yellow and wilt; the base of the rosette turns brown and soft, sometimes with white fungal threads at the soil line. Plants collapse in wet conditions.

Treatment

Remove and destroy affected plants. Improve drainage and avoid overhead watering. Do not mulch directly against the crown. Space plants for airflow and avoid replanting in the same wet spot.