Vernonia Summer's Swan Song

Similar in adaptability, bushiness, and fine texture to the popular selection Vernonia lettermannii ‘Iron Butterfly’, ‘Summer’s Swan Song’ grows somewhat larger, has larger capitula, and never lodges due to the elongated and interlocking inflorescence branches. The stems, leaves, and inflorescence branches also take on a dark red cast in full sunlight, adding to its display. The 1/3-inch-wide capitula with their dark purple florets are borne in profusion for five to six weeks from early September to mid-October. A diversity of butterflies, moths, and bees are attracted to the flowers. The fine foliage is a moderate-to-dark olive green and measures upward of 5 inches long and less than a quarter inch wide. Three-year-old plants of ‘Summer’s Swan Song’ measured 28 inches tall by 35 inches wide and 5-year-old plants measured 31 inches tall by 43 inches wide.

It has proven adaptable to both moist and dry soil, and has also exhibited excellent resistance to rust and powdery mildew. Use this selection individually or massed in perennial or mixed borders, in pollinator gardens, near lake edges, and other moist sites as long as well-drained, and in any situation that calls for a midsized attractive, and uniform perennial plant. 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 the wild ironweeds. 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 well-drained soil with reasonably uniform moisture availability. Cultivate in full sun and with good air circulation. 

The Summer’s Swan Song ironweed was selected in 2012 from a cross made in 2010 of Vernonia lettermannii and V. angustifolia ‘Plum Peachy’ by Dr. Jim Ault of The Chicago Botanic Garden. This was the first of our hybrid seedlings to catch their attention, and it never failed to impress in the subsequent trials.