Giant Ironweed
Vernonia gigantea
Varieties We Bring In
Last received Jul 19, 2026.
We bring this in seasonally, so what is on the lot changes week to week. A received date shows when it last came in, not that it is here today.
Call (904) 471-0440 to confirm this plant and size before you make the trip.
About Giant Ironweed
Giant Ironweed (Vernonia gigantea) is a Florida-native perennial wildflower reaching 3–10 feet tall, producing vivid purple-magenta flower clusters from July through October. Hardy throughout zone 9b (zones 8b–10b), it is an excellent pollinator plant for naturalistic gardens, meadows, and rain garden settings in NE Florida. Starting at $7.95.
Plant details
- Bloom Season
- Summer, Fall
- Flower Color
- Purple
- Growth Rate
- Fast
- Foliage
- Deciduous
- Soil
- Loam, Clay, Well-drained, Wet
Best planting months
Seasonal care
New foliage emerges. Good planting window.
Bloom season.
Bloom season. Foliage may begin to change or drop. Ideal planting window.
Dormant — drops foliage.
Care essentials
Plant Giant Ironweed in full sun to part sun; it blooms most prolifically in full sun. In NE Florida, it thrives in open meadow settings and naturalistic borders with at least 6 hours of direct light daily.
Prefers moderate to consistently moist soil; tolerates periodic wet conditions and clay. In NE Florida, it grows well in rain garden settings and low areas where summer rains naturally accumulate.
Adaptable to a wide range of soils including clay, loam, and moist areas. Little to no fertilizer needed—this native thrives in average to poor soil, and over-fertilizing promotes excessive height and flopping.
Similar needs
Alligator Flag
Shares 5 of the same needs: full sun, high water, loam, zone 9a hardiness, and pollinator-friendly.
Calla Lily
Shares 5 of the same needs: similar light, high water, loam, zone 9a hardiness, and pollinator-friendly.
Halberdleaf Rosemallow
Shares 5 of the same needs: full sun, high water, loam, zone 9a hardiness, and pollinator-friendly.
Scarlet Rosemallow
Shares 5 of the same needs: full sun, high water, loam, zone 9a hardiness, and pollinator-friendly.
Hardy Hibiscus
Shares 4 of the same needs: full sun, high water, loam, and pollinator-friendly.
American Hornbeam
Shares 5 of the same needs: full sun, high water, loam, zone 9a hardiness, and pollinator-friendly.
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Common questions
Is Giant Ironweed a good plant for St. Augustine?
Giant Ironweed is a perennial for Zone 9b coastal Florida gardens, reaching 3-10 feet × 2-4 feet.
Care information verified from
Last reviewed February 2026. Our care guidance comes from trusted horticulture sources and decades of helping St. Augustine gardeners. Conditions here can vary dramatically from one area to the next, so come ask us and we'll tailor it to your yard.