Image of Vernonia gigantea
image of Flowering plant
Vernonia gigantea
Giant ironweed
Vernonie géante

Obsolete Names

  • tall ironweed
No seeds available for this plant.

We are not accepting seeds for this plant at the moment.

Bloom colour: Purple Bloom period: August - September
Max Height: 5.0 feet
Max Width: 3.0 feet (spreads by rhizome)
Light condition:
Full sun More than 6 hours of direct sun a day
Part shade More than 2 or 3 hours but less than 6 hours of direct sun a day
Soil conditions:
Moisture medium Tolerates medium soil condition
Lifespan : Perennial
Gardener Experience:
does not spread Does not spread uncontrollably
plant germinate easy Easy to germinate
Landscape uses:
wetland garden Suitable for wetland garden
shoreline_rehab Suitable for shoreline rehabilitation
Ecological Benefits:
Pollinator garden Supports pollinators
butterfly host Butterfly host
bee host Bee host
Tolerates:
Deer Resistant Deer resistant
rabbit resistant Rabbit resistant
sand Tolerant Tolerates sandy conditions
acidic soil Tolerant Tolerates acidic soil conditions
juglone Tolerant Tolerates juglone conditions
transplantation Tolerant Tolerates transplantation

Plant Distribution

Native to Ottawa region: No

Distribution according to VASCAN

Distribution: Vernonia gigantea
Ephemeral Native Introduced Excluded Extirpated Doubtful Absent
View taxonomy on Canadensys

View on iNaturalist

Thrives in Ecozones

  • Ecozone-Mixed Wood Plain

Butterflies Supported by Vernonia gigantea

  • Phragmatobia fuliginosa (Ruby Tiger)
  • Vanessa virginiensis (American Lady)

Bees Supported by Vernonia gigantea

  • Megachile inimica
  • Melissodes denticulatus
  • Melissodes subillatus

Complementary Plants Plants that grow in similar conditions, that bloom at the same time.

  • No complementary plants found.

Sowing Information

  • Sowing depth: Sow just below surface
  • Sow before February
  • Stratification duration: 60 days
  • Self-seeding

Harvesting Information

  • Harvesting indicator: Seeds have become fluffy and can be easily removed by shaking on gently pulling off from stem
  • Harvesting mean: Shake seed head in paper bag
  • Seed Viability Test: No test needed before donating
  • Packaging Measure: 1 rounded 1/4 teaspoon
  • Seed Storage: Air Dry in paper bag or open container, for a few days until crisp, shaking seeds to move them once in a while to prevent molding
  • On Cultivar: Yes, do not donate unless you know source, and there are no known cultivars in your garden or at proximity