Vernonia, or commonly called ironweed, blooms late summer into fall, reaching heights of 3 to 4 feet. The dainty flowers are a great source of nectar for attracting butterflies and other beneficial insects. The fine textured foliage is enhanced by mass groupings of this rugged beauty. For optimal success, plant ironweed in full sun. It is very drought tolerant and does well in rocky, sandy, dry and infertile soils.