What hardiness zones is Kniphofia uvaria suitable for?

Kniphofia uvaria is suitable for USDA hardiness zones 5, 6, 7, 8, 9.

What are the sun requirements for Kniphofia uvaria?

Kniphofia uvaria requires Full Sun.

How much water does Kniphofia uvaria need?

Kniphofia uvaria has Low water needs.

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perennial

Kniphofia uvaria

Red Hot Poker

Asphodelaceae Cape Province, South Africa

At a Glance

TypePerennial

HabitClumping

FoliageSemi-evergreen

Height36-48 inches (90-120 cm)

Width24-30 inches (60-75 cm)

Maturity4 years

Growing Zones

USDA Hardiness Zones

5 - 9

Zone 5 Zone 6 Zone 7 Zone 8 Zone 9

These zones indicate the coldest temperatures this plant can typically survive.

What's my zone? →

Frost Tolerancehardy

Key Features

Attracts Pollinators Attracts Butterflies Attracts Hummingbirds Deer Resistant Drought Tolerant Container Friendly

Maintenancelow

Overview

Kniphofia uvaria is a clump-forming evergreen-to-semi-evergreen perennial with a basal rosette of stiff, strap-shaped leaves and erect flowering stems reaching 36-48 inches (90-120 cm) tall. Leaves measure 24-36 inches (60-90 cm) long and 1 inch (2.5 cm) wide, grey-green to blue-green, V-shaped in cross section, with finely toothed margins. The dense conical-to-cylindrical flower spike is 6-10 inches (15-25 cm) long, composed of 50-100 pendulous tubular florets each 1-1.5 inches (2.5-4 cm) long. Florets open from the bottom upward over 2-3 weeks; coral-red buds open to yellow at maturity, producing a two-tone spike. Bloom occurs from June through August in zones 5-7 and from May through July in zones 8-9. Plants spread slowly by short underground rhizomes, forming clumps 24-30 inches (60-75 cm) wide in 3-4 years. Foliage tips brown in winter in zones 5-6 and require trimming in spring. The crown rots in waterlogged soils, particularly during winter dormancy. Crown borer larvae and the variegated cutworm occasionally damage flower stalks. K. uvaria has naturalized in coastal grasslands of California, Oregon, southern Australia, and New Zealand, where it is regarded as a weed in pasture and natural-area settings.

Native Range

Native to Cape Province, South Africa, where it grows in damp grasslands, along streambanks, and on moist mountain slopes from sea level to 7,500 feet (2,300 m). Naturalized in California, Oregon, southern Australia, New Zealand, and parts of southwestern Europe.

Suggested Uses

Used in mixed perennial borders and dry-garden plantings spaced 24-30 inches (60-75 cm) apart, where the upright flower spikes contribute vertical line among lower-growing companions. Container plantings use pots of at least 7 gallons (26 L) with sandy well-drained mix; container specimens need winter protection in zones 5-7. Limited to USDA zones 5-9; crown rot is widespread in humid zones 10-11.

How to Identify

Identified by the dense bicolor poker-like flower spike with coral-red unopened buds at the apex and yellow open florets below, atop a leafless stem 36-48 inches (90-120 cm) tall above a basal rosette of grey-green V-shaped leaves. Distinguished from K. caulescens by the absence of a thick caudex, and from K. rooperi by narrower leaves and a more cylindrical (rather than ovoid) flower spike.

Appearance

Size & Dimensions

Height3' - 4'

Width/Spread2' - 2'6"

Reaches mature size in approximately 4 years

Colors

Flower Colors

red

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~8 weeks

Summer

Bloom occurs from June through August in zones 5-7 and from May through July in zones 8-9, with each spike opening over 2-3 weeks and a mature clump producing 5-10 spikes in succession over 6-8 weeks. Removal of spent stalks encourages a smaller second flush in late summer in zones 7-9. Bloom is reduced or absent in years following severe winter dieback in zones 5-6.

Detailed Descriptions

Flower Description

coral-red buds opening to yellow florets in a dense terminal spike

Foliage Description

grey-green to blue-green

Growing Conditions

Sun Requirements

Full Sun

Requires 6-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.5(Neutral)

357912

Soil Types

loam sand rocky

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

3-4 years to full clump

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Crowns are planted at soil level in spring after frost, spaced 24-30 inches (60-75 cm) apart in a site with sharp drainage. Weekly watering during the first growing season aids establishment; mature plants tolerate 2-4 weeks between rainfalls of 1 inch (2.5 cm). Annual fertilization is unnecessary in average soils; over-fertilized plants produce excess foliage and fewer flower spikes. Crown rot (Phytophthora and Pythium species) develops in waterlogged or poorly drained soils, particularly during winter; raised beds and gravel mulches reduce risk. In zones 5-6, a 4-6 inch (10-15 cm) layer of straw or pine-needle mulch applied in late autumn buffers the crown against freeze-thaw cycles. Clumps require division every 5-7 years in spring when bloom decreases or the center of the clump dies out.

Pruning

Spent flower stalks are cut at the base after seedhead formation to encourage a second flush and prevent self-seeding. In zones 5-6, foliage is left intact through winter and trimmed back in spring after new growth emerges; in zones 7-9, browned outer leaves are removed in late winter. Whole-clump cutbacks to 4-6 inches (10-15 cm) above ground reduce the subsequent year's bloom and are not part of routine maintenance.

Pruning Schedule

early springsummer

Maintenance Level

low

Container Growing

✓ Suitable for container growing

Minimum container size: 7 gallons

⚠️ Toxicity Warning

Non-toxic