Giant Ironweed
Vernonia gigantea
Found in pastures, bottomlands, streamsides, moist thickets, roadsides, disturbed wet or dry sands. FloraQuest, phone app (app page) What its natural habitat tells you
75
Strong
Native to Florida. How scores work Is it native here?
Profile 94%
- Height
- 3–12 feet
- Spread
- 3–6 feet
- Light
- Full sun, Partial shade
- Soil moisture
- Usually moist
Space about 4.5 ft apart from its recorded spread, about 5 per 100 sq ft. Enter your bed size for a count
Will it fit your yard?No photograph yet. Looking for an old drawing…
At a glance
- Life cycle
- Perennial
- Leaves
- Deciduous
- Bloom
- August to October
- Fruiting season
- August to November
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Recorded in 55 Florida counties.
Natural habitats
Places it grows wild. Not a planting requirement.
Habitats
Roadsides, fields and disturbed ground; floodplain and bottomland forests; streams, rivers and their banks; forest edges and thickets.
Each habitat page lists the plants and wildlife also found there. All habitats
Ecological relationships
Who uses this plant?
21CaterpillarsGenus host records with ranges including FL
Genus host records with ranges including FL · Vernonia
- Anavitrinella pampinariaCommon Gray, Cranberry Spanworm
- Archips rileyanaSouthern Ugly-Nest Caterpillar Moth
- Carmenta bassiformisEupatorium Borer Moth, Ironweed Clearwing Moth
- Chlorochlamys chloroleucariaBlackberry Looper Moth
- Dichomeris setosellaHairy Dichomeris
- Estigmene acreaSalt Marsh Moth, Acrea Moth
- Eupithecia miserulataCommon Eupithacia, Common Pug
- Hellinsia paleaceusOne-Spotted Plume Moth
- Papaipema baptisiaeWild Indigo Borer, Indigo Stem Borer
- Perigea xanthioidesRed Groundling
Show all 21
- Platynota idaeusalisTufted Apple-Bud Moth
- Pleuroprucha insulsariaCommon Tan Wave
- Polygrammodes flavidalisIronweed Root Moth, Vernonia Root-Borer
- Spodoptera ornithogalliYellow-Striped Armyworm Moth, Cotton Cutworm
- Synchlora frondariaSouthern Emerald
- Thyridopteryx ephemeraeformisEvergreen Bagworm Moth
- Vanessa virginiensisAmerican Lady, American Painted Lady
- Paralobesia sambuci
- Paralobesia vernoniana
- Polygrammodes oxydalis
- Thyraylia bunteana
46BeesSoutheastern regional records
Southeastern regional records · Vernonia
Individual names are not available yet.
Noori, Seltmann & Orr 2026, A curated and integrated dataset for exploring global bee-plant interactions (GloBI), Zenodo, CC BY 4.0
9Specialist beesPollen specialists
Pollen specialists · Vernonia
- Andrena placata
- Melissodes denticulatus
- Melissodes druriellus
- Melissodes microstictus
- Melissodes niveus
- Melissodes subillatus
- Melissodes trinodis
- Melissodes vernoniae
- Perdita octomaculata
—BirdsRecorded genus food-resource interactions; not a state feeding claimNo records yet · Ants · Beetles · Flies · Adult butterflies / moths · Other wasps · Other insects
Growing and identification
Plant details
- Family
- Asteraceae
- Hardiness
- Zones 5a–8b
- Soil pH
- Acidic to alkaline
- Flower color
- Purple
- Fruit begins
- August
- Fruit ends
- November
Safety has not been reviewed for this plant; check toxicity and thorns before planting.
Growing sources and scope
- Bloom · “Late August to October” · FloraQuest: Carolinas, Georgia (Southeastern Flora Team), phone app (app page) (ranked first; Prairie Moon 2026 Cultural Guide differs) · Carolinas and Georgia
- Flower color · “Purple” · NC Extension Plant Toolbox
- Fruit begins · “August” · FloraQuest: Carolinas, Georgia (Southeastern Flora Team), phone app (app page) · Carolinas and Georgia
- Fruit ends · “November” · FloraQuest: Carolinas, Georgia (Southeastern Flora Team), phone app (app page) · Carolinas and Georgia
- Hardiness · “Zones 5a–8b” · NC Extension Plant Toolbox
- Height · “3–12 feet” · NC Extension Plant Toolbox (ranked first; Prairie Moon 2026 Cultural Guide differs)
- Leaves · “Deciduous” · NC Extension Plant Toolbox
- Life cycle · “Perennial” · NC Extension Plant Toolbox
- Light · “Full sun (6 or more hours of direct sunlight a day); Partial shade (direct sunlight only part of the day, 2-6 hours)” · NC Extension Plant Toolbox (ranked first; Prairie Moon 2026 Cultural Guide differs)
- primary_flower_color · “purple” · Prairie Moon 2026 Cultural Guide
- Soil · “Moist” · NC Extension Plant Toolbox (ranked first; Prairie Moon 2026 Cultural Guide differs)
- Soil pH · “Acidic to alkaline” · NC Extension Plant Toolbox
- Spread · “3–6 feet” · NC Extension Plant Toolbox
Conservation status
| Florida rank | SNR |
|---|---|
| Global rank | G5 |
| FL status | Not verified |
| Federal status | Not verified |
In your garden
Will it fit your yard?
Check this plant against your county, sun and soil moisture. Conditions are checked in your browser.
Choose a county to begin.
Sources
- Atlas of Florida Plants
- USDA PLANTS
- Vascular Plants of North Carolina (NC Natural Heritage Program)
- FloraQuest: Carolinas, Georgia (Weakley), phone app (app page)
- FloraQuest: Florida (Weakley), phone app (app page)
- FloraQuest: Northern Tier (Weakley), phone app (app page)
- NatureServe Explorer
- Shropshire & Tallamy 2025, Lepidoptera of North America north of Mexico, ZooKeys 1261 (ODbL)
- Noori, Seltmann & Orr 2026, A curated and integrated dataset for exploring global bee-plant interactions (GloBI), Zenodo, CC BY 4.0
- Smith, Bachelder, Russell, Morales, Mosher & Seltmann 2024, Bee-Specialization-Modeling v0.6.1 (specialist host table compiled from J. Fowler's pollen specialist bee lists), Zenodo, CC BY 4.0
- Hurlbert, Olsen, Sawyer & Winner 2021, Avian Diet Database, Scientific Data 8: 260 (CC0)
- Narango, Tallamy & Shropshire 2020, Few keystone plant genera support the majority of Lepidoptera species, Nature Communications