Species Native to Missouri
Common Name: prairie ironweed
Type: Herbaceous perennial
Family: Asteraceae
Native Range: South-central Canada to central and eastern United States
Zone: 4 to 9
Height: 2.00 to 4.00 feet
Spread: 1.50 to 3.00 feet
Bloom Time: July to September
Bloom Description: Purple
Sun: Full sun
Water: Medium to wet
Maintenance: Low
Suggested Use: Naturalize, Rain Garden
Flower: Showy
Tolerate: Deer, Wet Soil
Culture
Easily grown in average, medium to wet soils in full sun. Although it is mostly seen growing in the wild in moist soils, with tolerance for periodic but brief flooding, it performs quite well in cultivation in average garden soils. Plants generally grow taller in moist soils. Overall plant height may be reduced by cutting back stems in late spring. Easily grown from seed. Remove flower heads before seed develops to avoid any unwanted self-seeding. This species of ironweed tends to hybridize with other native ironweeds, which can sometimes complicate plant identification.
Noteworthy Characteristics
Vernonia fasciculata is commonly called smooth ironweed because its leaves, stems and flower heads are distinctively glabrous. It is native from Ohio to North Dakota south to Missouri, Oklahoma and Texas. In Missouri, it typically occurs in low moist prairies and in swampy river bottom meadows north of the Missouri River and in the western part of the State (Steyermark). This is an upright perennial that typically grows 2-4’ (infrequently to 5’) tall on stiff, leafy stems which branch at the top. Narrow, linear to lance-shaped leaves (to 5” long) have serrated margins. Composite flowers, each with dense, fluffy, purple disks (rays absent), bloom in dense, fastigiately clustered, corymbose cymes from late summer into fall. Flowers give way to rusty seed clusters. The source of the common name for vernonias has been varyingly attributed to certain “iron-like” plant qualities including tough stems, rusty-tinged fading flowers and rusty colored seeds. Notwithstanding its toughness, the plant is, with the exception of its attractive flowers, a somewhat unexceptional ornamental. Flowers are very attractive to butterflies.
Genus name honors William Vernon (d. c. 1711), English botanist who collected in Maryland in 1698.
Specific epithet means in a bundle or cluster.
Problems
No serious insect of disease problems.
Uses
Naturalize in cottage gardens, wildflower meadows, prairies or native plant gardens. Also effective as a background plant for borders.