Gray Narrowleaf Ironweed

Vernonia lettermannii

Family: Asteraceae (ass-ter-AY-see-ee) (Info)
Genus: Vernonia (ver-NON-ee-uh) (Info)
Species: lettermannii (let-ter-MAH-nee-eye) (Info)



Foliage Color:

Unknown - Tell us

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Requires consistently moist soil; do not let dry out between waterings

Where to Grow:

Unknown - Tell us


24-36 in. (60-90 cm)


12-15 in. (30-38 cm)

15-18 in. (38-45 cm)

18-24 in. (45-60 cm)


USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

Sun Exposure:

Full Sun


Unknown - Tell us

Bloom Color:


Bloom Time:

Late Summer/Early Fall

Mid Fall



Other details:

Unknown - Tell us

Soil pH requirements:

Unknown - Tell us

Patent Information:


Propagation Methods:

From herbaceous stem cuttings

From seed; direct sow outdoors in fall

From seed; winter sow in vented containers, coldframe or unheated greenhouse

Self-sows freely; deadhead if you do not want volunteer seedlings next season

Seed Collecting:

Unknown - Tell us


This plant has been said to grow in the following regions:

North Little Rock, Arkansas

Lawrence, Kansas

High Point, North Carolina

West Chester, Pennsylvania

Gardeners' Notes:


On Nov 19, 2015, cactusman102 from Lawrence, KS wrote:

Great perennial once established; fine texture looks like amsonia. Winter dried foliage and seed heads look very attractive and hold up most of the winter. Protect from rabbits for the first year.


On Jun 28, 2014, Rickwebb from Downingtown, PA wrote:

This not well-know perennial comes from Oklahoma and Arkansas that is also called Threadleaf Ironweed. Does well in southeast PA and probably does well over much of the East and Midwest in any good quality soil or in rough, sandy, infertile, dry soils, sort of acid to sort of alkaline. Handsome perennial with fine texture and fuzzy purple flowers in late summer and early fall that are good for pollinators. In nature it was found growing on gravel bars and in cracks on rocks in river drainage areas. Scientific name refers to George Letterman, a botanist who lived in a cabin, west of St Louis, Missouri, and looked for rare plants in his region.