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Native alternative(s) for Vernonia gigantea:
Vernonia noveboracensis Form
Plants that fill a similar niche:
Viola sororia Viola papilionacea
Salvia azurea Salvia azurea 'Nekan' flowers with bee
Vernonia noveboracensis Form

Vernonia gigantea

Common Name(s):

Previously known as:

  • Vernonia altissima
Phonetic Spelling
ver-NOH-nee-ah jy-GAN-tee-uh
Description

Giant ironweed is a native herbaceous perennial wildflower in the Asteraceae or daisy family. This plant has a tall narrow habit that appears in the spring. The plant usually grows from 3 to 5 feet tall, but it has been known to grow to a height of 12 feet.  Lavender, magenta, or deep purple flowers appear in late summer to early fall. The seeds are tiny achenes that have tufts of bristles that are easily dispersed by the wind.

Giant ironwood or tall ironwood is native to the southeast and the central United States and central Canada. It may be found naturally in prairies, grasslands, floodplains, woodlands, along roadsides, and near stream banks or forests edges. The plant is commonly found in overgrazed pastures. Livestock usually does not eat this plant resulting in the germination of the many seeds.

The genus name, Vernonia, is in honor of an English botanist, William Vernon. The species name, gigantea, is Latin and means "of giants." The common name, ironwood, refers to the toughness of the stems of the plant.

Giant ironwood prefers full sun to partial shade and well-drained moist to wet soils. They are tolerant of all soil pH and grow well in a mixture of loam, clay-loam, or sandy-loam soils. Cutting back the plant early in the season will reduce its height. Deadheading of the spent blooms will encourage continued flowering. This plant is easily propagated by seed or division.

The stem is tall, erect, stiff, and rounded. Atop the stem is a flat-headed panicle of flower heads that measures up to 16 inches across. Each flower head has 10-30 florets of lavender, magenta, or deep purple. Each floret is tubular that opens distally with 5 petals or lobes. The leaves are dark green on the upper surface and paler green and slightly hairy beneath. The fruits are grayish-brown achenes.

Butterflies and bees are attracted to this pollinator plant. Most small mammals and livestock avoid it due to the bitter-tasting foliage. 

This native plant may be easily grown in a cottage garden, wildflower garden, or pollinator garden. Due to its height, it is best planted in the back of a border garden.  It will compete with other plants in the garden and can become weedy if not controlled.

Seasons of Interest:

Bloom: Late Summer and Fall         Foliage:  Spring and Summer       Fruits:  Fall

Quick ID Hints:

  • tall, erect, stiff, rounded, green stem from 3 to 12 feet tall
  • dark green ovate, oblanceolate to elliptical leaves, measuring up to 9 inches long and up to 2.5 inches wide with serrated margins
  • atop central stem is a flat-headed panicle of flower heads of lavender, magenta, or deep purple that measure 6 to 16 inches in diameter
  • each flower head has 10-30 florets that are tubular shaped
  • fruits are gray to brown achenes with a tuft of short and long hairs

Pests, Diseases, and Other Plant Problems:  Giant ironwood has no serious problems with pests or diseases. Caterpillars of some moths may feed on the stems and roots of the plant. Aphids may be seen ingesting the juice of the stems and leaves. Crickets and katydids have been observed eating the flowerheads. 

VIDEO created by Andy Pulte for “Landscape Plant Identification, Taxonomy and Morphology” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.

 

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Cultivars / Varieties:
Tags:
#showy flowers#full sun tolerant#purple flowers#low maintenance#cottage garden#seeds#NC native#deer resistant#native garden#division#border planting#green leaves#NC Native Pollinator Plant#flowers late summer#border back#wet soils tolerant#butterfly friendly#flowers early fall#partial shade tolerant#bee friendly#native#tall plant#butterfly garden#landscape plant sleuths course
 
Cultivars / Varieties:
Tags:
#showy flowers#full sun tolerant#purple flowers#low maintenance#cottage garden#seeds#NC native#deer resistant#native garden#division#border planting#green leaves#NC Native Pollinator Plant#flowers late summer#border back#wet soils tolerant#butterfly friendly#flowers early fall#partial shade tolerant#bee friendly#native#tall plant#butterfly garden#landscape plant sleuths course
  • Attributes:
    Genus:
    Vernonia
    Species:
    gigantea
    Family:
    Asteraceae
    Life Cycle:
    Perennial
    Recommended Propagation Strategy:
    Division
    Seed
    Country Or Region Of Origin:
    Southeastern to Central United States and Central Canada
    Distribution:
    Native: Canada--Ontario; United States--AL, AR, FL, GA, IL, IN, KS, KY, LA MD, MI, MS, MO, NE, NY, NC, OH, OK, PA, SC, TN, TX, VA, and WV. Introduced: India
    Wildlife Value:
    It attracts many pollinators including bees and butterflies.
    Play Value:
    Attractive Flowers
    Attracts Pollinators
    Easy to Grow
    Particularly Resistant To (Insects/Diseases/Other Problems):
    Deer resistant and wet soil resistant
    Dimensions:
    Height: 3 ft. 0 in. - 12 ft. 0 in.
    Width: 3 ft. 0 in. - 6 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Herbaceous Perennial
    Native Plant
    Perennial
    Wildflower
    Woody Plant Leaf Characteristics:
    Deciduous
    Habit/Form:
    Erect
    Maintenance:
    Low
    Texture:
    Coarse
  • Cultural Conditions:
    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
    Shallow Rocky
    Soil pH:
    Acid (<6.0)
    Alkaline (>8.0)
    Neutral (6.0-8.0)
    Soil Drainage:
    Good Drainage
    Moist
    Available Space To Plant:
    3 feet-6 feet
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    5b, 5a, 6b, 6a, 7b, 7a, 8b, 8a
  • Fruit:
    Fruit Color:
    Brown/Copper
    Gray/Silver
    Display/Harvest Time:
    Fall
    Fruit Type:
    Achene
    Fruit Length:
    < 1 inch
    Fruit Width:
    < 1 inch
    Fruit Description:
    Each floret is replaced by achene that is gray to brown. Attached to each achene are short and long hairs that are pale purple or yellowish-brown. This allows the seed to be easily dispersed by the wind.
  • Flowers:
    Flower Color:
    Purple/Lavender
    Flower Inflorescence:
    Panicle
    Flower Value To Gardener:
    Long Bloom Season
    Showy
    Flower Bloom Time:
    Fall
    Summer
    Flower Petals:
    4-5 petals/rays
    Flower Size:
    < 1 inch
    Flower Description:
    Atop the central stem is a flat panicle of flower heads that measure 6 to 16 inches in diameter. Each flower head disk has 10-30 disk florets. The florets are shaped like flared tubes. Each of the tubes has 5 petals or lobes that are fused at the base and separate at the top. Blooming lasts from 1 to 1.5 months and occurs in the late summer to early fall.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Deciduous
    Leaf Color:
    Green
    Leaf Type:
    Simple
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Elliptical
    Oblanceolate
    Ovate
    Leaf Margin:
    Serrate
    Hairs Present:
    Yes
    Leaf Length:
    > 6 inches
    Leaf Width:
    1-3 inches
    Leaf Description:
    The leaves are alternate, ovate, oblanceolate, or elliptical with serrated margins. The leaves are distributed along the stem. They measure 4 to 12 inches long and up to 2.5 inches wide. The upper surface of the leaf is dark green and smooth. The lower surface is pale green and smooth to slightly hairy.
  • Stem:
    Stem Color:
    Green
    Purple/Lavender
    Stem Is Aromatic:
    No
    Stem Cross Section:
    Round
    Stem Form:
    Straight
    Stem Surface:
    Hairy (pubescent)
    Stem Description:
    The stem is tall, stiff, erect, and light green to purplish green. It may be almost smooth or hairy
  • Landscape:
    Landscape Location:
    Meadow
    Naturalized Area
    Vertical Spaces
    Landscape Theme:
    Butterfly Garden
    Cottage Garden
    Native Garden
    Pollinator Garden
    Design Feature:
    Accent
    Border
    Specimen
    Attracts:
    Bees
    Butterflies
    Resistance To Challenges:
    Deer
    Wet Soil
    Problems:
    Weedy