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Ironweed

Vernonia lettermannii (ver-NON-ee-ah let-ter-MAN-ee-eye)

Family: Asteraceae Unknown Herbaceous (3-15 ft)

Letterman’s Ironweed is a herbaceous perennial native to Arkansas and Oklahoma in the aster family (Asteraceae). In its native habitat, it grows on rocky outcrops, floodplains, and river scours. The genus was named after the English botanist William Vernon, and the specific epithet after the American botanist George W. Letterman. The upright plant can be 2 feet tall and wide. Easily grown in a variety of soils, including shallow-rocky soils. Fertile soils may cause bending and arching stems. For best flowering and to maintain the erect stems, plant in full sun with moist, well-drained soil. Once established, it will tolerate occasional flooding and drought. Prune in late winter or early spring. Propagate by division or seeds. The frilly purple blooms are visited frequently by butterflies, hummingbirds, and bees in mid to late summer. Plant in pollinator gardens, native gardens, and sunny mass plantings. They are adaptable to slopes and rock gardens. The late-season purple blooms contrast well with yellow goldenrods. Insects, Diseases, and Other Plant Problems: No major pest or disease problems.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 55 attributes.

How it fits the guild

Guild layer 4 - Herbaceous (3-15 ft) Optimal soil pH Neutral (6.0-8.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Full plant profile

Growing Conditions
Plant type
Herbaceous Perennial; Wildflower
Life cycle
Perennial
USDA zones
4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Light
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; Loam (Silt); Sand
Soil pH
Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist | Occasional Flooding | Occasionally Dry
Available space
3 feet-6 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 2 ft. 0 in. - 3 ft. 6 in. | Width: 2 ft. 0 in. - 3 ft. 0 in.
Growth rate
Medium
Maintenance
Low
Canopy layer
4 - Herbaceous (3-15 ft)
Form & Appearance
Habit / form
Dense; Erect; Mounding
Texture
Fine
Foliage
Deciduous
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Alternate
Leaf shape
Linear
Leaf margin
Entire
Leaf value
Showy
Leaf size
1-3 inches long, < 1 inch wide
Hairs present
No
Leaf detail
Leaves are up to 3 inches long and 1/8 inch wide and are finely textured.
Flower color
Purple/Lavender
Flower value
Good Cut; Showy
Flower form
Corymb
Flower shape
Tubular
Flower size
< 1 inch
Flower detail
Flowers are very tight clusters of tiny tubular purple disc flowers. Blooms mid to late summer.
Bloom time
Summer
Fruit color
Brown/Copper; Gray/Silver; Purple/Lavender
Fruit type
Achene
Fruit detail
Brown to gray nutlet with a bristly brown to purple colored pappus.
Stem color
Green
Stem detail
Green stems
Wildlife & Ecology
Native status
Unknown
Origin
Arkansas and Oklahoma
Wildlife value
Attracts pollinators
Attracts
Bees; Butterflies; Hummingbirds
Food & Medicine
Fruit type
Achene
Landscape Use
Landscape location
Naturalized Area; Slope/Bank
Landscape theme
Cutting Garden; Native Garden; Pollinator Garden; Rain Garden; Rock Garden
Design feature
Border; Mass Planting; Small groups
Garden tags
#mounding #rock garden #showy flowers #drought tolerant #hummingbird friendly #pollinator plant #deciduous #purple flowers #butterfly friendly #full sun tolerant #bee friendly #perennial #wildlife friendly #herbaceous perennial #cottage garden #native garden #pollinator garden #moth friendly
Problems & Resistance
Resistant to
Deer; Drought; Dry Soil; Erosion; Rabbits
Propagation
Root Cutting; Seed

Planted at Hunnicutt

Nobody’s planted this one yet.