Echinacea superstars

Editor’s note: Information published with permission from the Mt. Cuba Center Echinacea report.

Echinacea, commonly known as coneflowers, are among the most iconic and recognizable native plants in North America. The earliest documented horticultural use of Echinacea can be traced to the late 17th century when Echinacea purpurea seeds were sent to England by the Virginia clergyman and naturalist John Banister. Medicinal use dates back even further as Native Americans used Echinacea to treat a variety of ailments, a tradition that has carried into modern times.

The nine species of Echinacea are North American natives and predominantly occur in the central and eastern United States. The majority of wild coneflowers display pink, purple, and rarely white flowers from late spring to summer. Only one species, Echinacea paradoxa, breaks this color trend and produces canary yellow blooms in June. Dr. Jim Ault of the Chicago Botanic Garden was among the first plant breeders to intentionally cross multiple species in the 1990s. Since that time, the breeding and selection of coneflower species has further unlocked the horticultural potential of this genus resulting in a staggering variety of new cultivars in American and European horticultural markets. Today, Echinacea are available in an array of colors including, white, yellow, orange, red, pink, purple, and even green.

Double, or pompom, flower forms also add to the diversity of coneflowers.

Although common in gardens, some coneflowers are threatened in the wild. Echinacea laevigata is federally endangered due to habitat loss and the suppression of fires that are key to its survival. Echinacea tennesseensis was also considered endangered but was delisted in 2011 thanks to conservation efforts.

However, it still only exists in a relatively small range in Tennessee. Other species, particularly Echinacea angustifolia, are under pressure from unsustainable wild harvests due to their purported medicinal qualities. Thankfully, an increased availability of commercially farmed Echinacea has reduced some of the stress on wild coneflower populations. To ensure the future of wild coneflowers, it is important to only purchase commercially produced herbal supplements and nursery propagated plants.

Echinacea, like the previously trialed Coreopsis and Helenium, are members of the aster family (Asteraceae). An Echinacea “flower” is a composite inflorescence made up of hundreds of individual ray and disc flowers, or florets. Fertile disc flowers form the center, or cone, of the flower. Each disc flower is accompanied by a single spiny bract that together gives coneflowers their signature bristly appearance. In fact, the genus name Echinacea originates from “echinos,” the Greek word for hedgehog. Individual disc flowers are short-lived but collectively offer pollen and nectar to pollinators or an average of five weeks from late spring through summer.

The individual colorful “petals” of Echinacea blooms are actually specialized ray flowers that serve to attract pollinators. With ray flowers included, most coneflower inflorescences range from 3-5 inches in diameter.

Double-flowered Echinacea represent significant breakthroughs in coneflower breeding that have increased the variety of the genus in the horticultural market. They have become popular in gardens because of their showy flowers and prolonged bloom times but have proved to be less favored by pollinators.

Echinacea are clump-forming herbaceous perennials that emerge each spring to form a lush rosette of lanceolate foliage. Some species, including E. purpurea, produce leaves with relatively few foliar hairs while others, like E. pallida and E. tennesseensis, are densely pubescent. In mid- to late spring, flowering stems push their way above the basal foliage and eventually reach a height of 2-4 feet depending on the species or cultivar. Seeds ripen in late summer and are readily consumed by birds, particularly goldfinches.

Most coneflowers produce taproots that allow them to grow in competitive habitats where water is at a premium. In contrast, E. purpurea produces roots that are more fibrous and are consequently better suited for average garden soil. All coneflowers, however, require soils that are well-drained to persist and thrive in a garden setting.

Echinacea top performers

A few coneflowers, specifically Echinacea purpurea ‘Pica Bella’ and Echinacea purpurea ‘Fragrant Angel’ were included in our 2007–2009 and 2018–2020 Echinacea trials and constituted some of the best performing plants in both evaluations. Top performing Echinacea overall had sturdy, semi-compact habits that resisted flopping and largely omitted the need for staking, a trend that was also observed in our first evaluation of the genus.

One common problem with coneflowers is that some do not live long in the garden. It has been theorized that cultivars grown from seeds are longer-lived and generally more vigorous than coneflowers that are produced clonally in tissue culture. Unfortunately, due to the infection rates of a disease called aster yellows (see full report mtcubacenter.org/trialgarden) it was difficult to determine what the natural life span of various cultivars would be in the absence of the pathogen

PHOTO COURTESY OF MT. CUBA

Echinacea purpurea ‘Pica Bella’

‘Pica Bella’ ranked among the top-performing coneflowers in our first trial in 2009 and is again one of the most outstanding cultivars we evaluated. ‘Pica Bella’ is a compact and floriferous form of the species that originated as a seedling of Echinacea purpurea ‘Abenstem’. While many Echinacea cultivars in the market today showcase vibrant blooms that can look out of place in a naturalistic setting, the floral display of ‘Pica Bella’ resembles that of Echinacea purpurea, allowing for its effortless incorporation into a broad range of garden designs. In addition to excelling in all horticultural aspects, this cultivar was also a favorite among pollinators that flocked to its prominent orange cones. Echinacea purpurea ‘Pica Bella’ has withstood the test of time and proven once again that it deserves a place in gardens of the mid-Atlantic region.

Echinacea ‘Santa Fe’

Echinacea ‘Santa Fe’ is a seed-produced cultivar from the Proven Winners LAKOTA Series of coneflowers. Despite some expected variation in seed strains, Echinacea ‘Santa Fe’ showed remarkable consistency in our trial and was similar in many ways to Echinacea ‘Balsomcor’ (SOMBRERO® Hot Coral), although ‘Santa Fe’ was decidedly more vigorous. This tidy and well-branched plant reaches 2 feet tall and wide at maturity. Striking coral-red flowers are produced en masse from late June through late July before eventually fading to attractive shades of pastel pink. Echinacea ‘Santa Fe’ not only scored as a top performer in the trial, but it was also popular with trial garden visitors who voted it among their top five favorites in both 2018 and 2019.

Echinacea ‘Sensation Pink’

A product of the breeding efforts of Marco van Noort in the Netherlands, Echinacea ‘Sensation Pink’ produced one of the most vibrant displays in our trial. Intense, neon-pink flowers are held on dark stems that further accentuate their otherworldly floral color. In contrast to the exuberant blooms, ‘Sensation Pink’ manifests a restrained and more compact habit relative to its wild counterparts. While ‘Sensation Pink’ is undoubtedly a horticultural standout, it proved to have substantial ecological value as well. In fact, this cultivar was one of the five most pollinator-visited Echinacea in the trial. This is one truly sensational plant.

Echinacea ‘Snow Cone’

Echinacea ‘Snow Cone’ is an outstanding cultivar introduced by Intrinsic Perennial Gardens in Hebron, Illinois. This pocket-sized hybrid is one of the most compact coneflowers in our trial. Fully grown, it reaches 2 ½ feet in height and width, making it a perfect choice for container gardens or the front of a border. Despite its modest size, ‘Snow Cone’ puts on a first-class floral display from the middle of June through late July. During peak bloom, this cultivar’s foliage is almost completely obscured by a profusion of 3-inch snowy white blossoms. In addition to a standout floral display, ‘Snow Cone’ is reputed to be a long-lived plant, a trait associated with its E. tennesseensis parentage.

Echinacea ‘TNECHKR’ (KISMET^® Raspberry)

Echinacea ‘TNECHKR’, also known by the trade name KISMET Raspberry, is one of several Terra Nova Nurseries introductions that were evaluated in this trial. KISMET® Raspberry was a standout in the trial thanks to its strong vigor, saturated color, and oversized blooms. The glowing raspberry-pink petals are at their peak in early July and, while comparable to the blooms of Echinacea ‘Sensation Pink’ and Echinacea ‘Purple Emperor’, KISMET® Raspberry maintains the slightest floral edge over these close competitors because of the sheer vibrancy of its blooms. KISMET® Raspberry hybrid coneflower has an attractive and consistent 3-foot-by-3-foot habit, similar to that of E. purpurea ‘Pica Bella’.