Vernonia Summer's Surrender

‘Summer’s Surrender’ is no shrinking-violet perennial, as it matures into a robust yet uniform and dense broad mound. With excellent resistance to both powdery mildew and rust, the foliage remains clean and attractive all summer and fall. The olive green leaves grow to 5 inches long and half an inch wide. Dark purple florets are packed into nearly 1-inch-wide flower heads, which are borne in profusion on airy inflorescences from early September to early October.

A diversity of butterflies, moths, and bees are attracted to the flowers. Plant in full sun and reasonably well-drained soil. It has proven adaptable to both moist and drier soil. Use this selection in the back of larger perennial or mixed borders, near lake edges and other moist sites, in pollinator gardens, and in any situation that calls for a larger yet attractive and uniform perennial plant. Most ironweed taxa are native to mesic and even wet habitats.

One of the parents (V. lettermannii) used in developing these selections is less typically found in rocky, upland habitats. Our selections seem to have inherited both tolerances, withstanding both high soil moisture and periods of drought. Best to provide a well-drained soil with reasonably uniform moisture availability. Cultivate in full sun and with good air circulation. Both selections form robust fibrous root systems. Utilize mulch around the plants to preserve soil moisture on drier soils. Staking isn’t required if properly grown. Only a few stems have ever been observed to lodge on ‘Summer’s Surrender’.

The native ironweeds (Vernonia species) are important pollinator plants in natural habitats throughout the eastern and central United States. They are easy to cultivate, yet relatively few garden cultivars have been developed, no doubt due to their often rangy habits and robust sizes. Dr. Jim Ault at the Chicago Botanic Garden has tamed their wild ways!  By combining the best traits of different species, we have developed garden-worthy selections that not only bloom for all of September, attracting a plethora of pollinators but are more uniform, durable, and disease-resistant than wild ironweeds.

The Summer’s Surrender ironweed was selected in 2013 from a 2010 cross of Vernonia lettermannii and V. arkansana made by Dr. Jim Ault at The Chicago Botanic Garden. It inherited the bushy habit of V. lettermannii and the more robust plant size, larger foliage, and larger capitula of V. arkansana.