Kniphofia caulescens 'John May'

RHS Plant Profile

caulescent red-hot poker 'John May'

Synonyms

Kniphofia caulescens 'John May's Form'
Kniphofia caulescens from John May

Herbaceous Perennial

An evergreen perennial to 1m tall with long, grey-green leaves. In summer and autumn, the stout, bronze-tinged stems bear heads of pinky-bronze buds opening to coral-red flowers fading to yellow with age

Position

Full sun

Soil Types

Loam, Sand

Max Height

1-1.5 metres

Max Spread

0.5-1 metres

Size

Time to Maturity: 2–5 years
Max Spread: 0.5-1 metres
Max Height: 1-1.5 metres

Growing Conditions

Loam Sand

Moisture: Moist but well–drained
pH: Acid or Neutral

Position

Full sun

Aspect: West–facing or South–facing
Exposure: Exposed or Sheltered
Hardiness

Hardiness Ratings

All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

H1A: under glass all year (>15C)
H1B: can be grown outside in the summer (10 - 15)
H1C: can be grown outside in the summer (5 - 10)
H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
H4: hardy through most of the UK (-10 to -5)
H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
H6: hardy in all of UK and northern Europe (-20 to -15)
H7: hardy in the severest European continental climates (< -20): H5

Colour & Scent

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Asphodelaceae
Native to GB/Ireland: No
Foliage: Evergreen
Habit: Tufted
Genus: Kniphofia may be evergreen or herbaceous perennials, with linear or strap-shaped leaves and erect stems bearing a dense raceme of tubular, usually pendent flowers
Name Status: Accepted

How to Grow

Cultivation

Grow in full sun and fertile, moist but well-drained soil that isn’t too wet over winter. See kniphofia cultivation for further advice

Propagation

Propagate by division of established clumps in late spring. Propagate by taking offshoots from the crown

Suggested planting locations and garden types

Coastal
Gravel garden
Flower borders and beds

Pruning

Cut down old flower stems after flowering; old or dead leaves can be tidied up or removed in mid-spring

Pests

May be susceptible to aphids, thrips, slugs and snails

Diseases

Generally disease-free