Vernonia Species, Giant Ironweed, Tall Ironweed

Vernonia gigantea

Family
Asteraceae (ass-ter-AY-see-ee)
Genus
Vernonia (ver-NON-ee-uh)
Species
gigantea (jy-GAN-tee-uh)
Synonym
Chrysocoma gigantea
Chrysocoma praealta
Vernonia oligantha
Vernonia ovalifolia
Sun Exposure
Sun to Partial Shade
Foliage
Herbaceous
This plant is resistant to deer
Succulent
Height
6-8 ft. (1.8-2.4 m)
Spacing
12-15 in. (30-38 cm)
Hardiness
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)
Danger
Handling plant may cause skin irritation or allergic reaction
Bloom Color
Magenta (pink-purple)
Fuchsia (red-purple)
Blue-Violet
Lavender
Medium Purple
Bloom Time
Mid Summer
Other Details
Category
Perennials
Water Requirements
Foliage Color
Where to Grow
Bloom Characteristics
This plant is attractive to bees, butterflies and/or birds
Bloom Size
Other details
May be a noxious weed or invasive
Soil pH requirements
5.6 to 6.0 (acidic)
6.1 to 6.5 (mildly acidic)
6.6 to 7.5 (neutral)
Patent Information
Non-patented
Propagation Methods
From seed; direct sow outdoors in fall
From seed; stratify if sowing indoors
Self-sows freely; deadhead if you do not want volunteer seedlings next season
Seed Collecting
Allow seedheads to dry on plants; remove and collect seeds
Regional

This plant is said to grow outdoors in the following regions:

Auburn, Alabama

Hanceville, Alabama

Morrilton, Arkansas

Richmond, California

Sacramento, California

Wethersfield, Connecticut

Fort Lauderdale, Florida

Lake Wales, Florida

Mayo, Florida

Pensacola, Florida

Cornelia, Georgia

Demorest, Georgia

La Grange Park, Illinois

Minooka, Illinois

Barbourville, Kentucky

Melbourne, Kentucky

Salvisa, Kentucky

Allen Park, Michigan

Midland, Michigan

Saint Paul, Minnesota

Croton On Hudson, New York

Pomona, New York

Lake Toxaway, North Carolina

Bowling Green, Ohio

Columbus, Ohio

Fort Jennings, Ohio

Guysville, Ohio

Hamilton, Ohio

Carlisle, Pennsylvania

Lewisburg, Pennsylvania

Millersburg, Pennsylvania

Pennsburg, Pennsylvania

Clarksville, Tennessee

Collierville, Tennessee

Maryville, Tennessee

Arlington, Texas

Princeton, Texas

Santa Fe, Texas

Kalama, Washington

Spencer, West Virginia

show all

Featured Videos

Gardener's Notes:

6
positives
1
neutral
0
negative
Sort By:
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B
Mount Ivy, NY | July 2020 | positive

This plant is a favorite of all pollinators. Right now, my largest one is about 6 feet and already starting to make buds in my zone 6b ga...Read More

L
L
Hanceville, AL (Zone 7a) | September 2012 | positive

I rate this one as lovely. It grows wild here but I could not get the seeds I collected to germinate. So I found a source of seed on-li...Read More

C
C
Lewisburg, PA (Zone 6b) | July 2012 | positive

In its second year in the perennial garden this plant has formed a bushel-sized clump and has reached 9' tall. It is tied to a fence post...Read More

M
M
Columbus, OH (Zone 5b) | August 2009 | positive

This is truly a massive plant with almost flourescent purple blooms. Unfortunately, the bloom period is limited to about three weeks. The...Read More

J
Sacramento, CA (Zone 9a) | July 2007 | positive

I love it. I've had it for several years in my backyard in Sacramento, CA. It hasn't become invasive for me and hasn't reseeded or spre...Read More

B
Culpeper, VA (Zone 7a) | September 2005 | positive

This lovely wildflower is just coming into its own this time of year (September). Indigenous here - the Piedmont area of VA - it enjoys ...Read More

J
Spencer, WV | April 2004 | neutral

This woody weed can get quite tall, often towering over the cattle in the pastures where it thrives. It seems to like moist areas, and ...Read More

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