Vernonia arkansana

RHS Plant Profile

Arkansas ironweed

Synonyms

Vernonia crinita

Herbaceous Perennial

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A clump-forming perennial to 2m tall with upright stems clothed in narrow lance-shaped leaves. In autumn, loose clusters of small pinkish-purple flowers are borne on branched stems

Position

Full sun, Partial shade

Soil Types

Chalk, Clay, Loam

Max Height

1.5-2.5 metres

Max Spread

1-1.5 metres

Size

Time to Maturity: 2–5 years
Max Spread: 1-1.5 metres
Max Height: 1.5-2.5 metres

Growing Conditions

Chalk Clay Loam

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

Position

Full sun Partial shade

Aspect: South–facing or East–facing or West–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): H7

Colour & Scent

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Asteraceae
Native to GB/Ireland: No
Foliage: Deciduous
Habit: Clump forming
Genus: Vernonia are annuals, perennials, climbers, sub-shrubs, shrubs and trees, though only the perennials are in cultivation. They have upright stems, simple, stalkless leaves and flat branched heads of tubular purple or reddish pink, occasionally white, flowers
Name Status: Correct
Plant Range: North America

How to Grow

Cultivation

Grow in a light, moderately fertile, moist soil preferably in full sun but will tolerate partial shade

Propagation

Propagate by seed or by division

Suggested planting locations and garden types

Cottage and informal garden
Prairie planting
Wildlife gardens
Flower borders and beds

Pruning

Deadhead to prolong flowering and, if necessary, to prevent self-seeding

Pests

Generally pest-free

Diseases

Generally disease-free