Echinacea Explosion - The Purple Coneflower Chronicles
Plant Delights Nursery, Inc.
9241 Sauls Road
Raleigh, NC 27603
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Introduction to the Genus Echinacea - Coneflowers
It is not an exaggeration to say that purple coneflower is the one of the finest native perennials in the United States. Echinacea is a native plant that produces large, conspicuous flowers over a long period of time. Purple coneflower is tough, drought tolerant, easy to grow, attracts wildlife to the garden, and cold hardy in almost every state. In short, coneflower plants have a lot going for them. The last 10 years of Echinacea breeding have been nothing short of amazing. Gardeners have been blessed with incredible breakthroughs in color, flower form, and even scent. You can stimulate your garden (and your immune system) by growing these!
We at Plant Delights Nursery and Juniper Level Botanic Gardens grow many wonderful, new, and rare echinacea. We currently have 65 accessions of Echinacea in the garden and we offer the finest and most unique cultivars for sale through our mail order nursery. We urge our readers to visit the garden during our Open Nursery and Garden Dates to see our collection and check out our web site to view our offerings.
History and Background of Echinacea
The original purple coneflower, Echinacea purpurea, was discovered by European explorers in the forests of the southeastern US in the 17th century and was first sent to England in 1699 by the natural historian and Reverend, John Banister who had been sent to Virginia to study American flora and fauna.
The common name for most Echinacea species is 'purple coneflower'. That is a bit of a misnomer as not every Echinacea has purple flowers. Echinacea paradoxa has yellow flowers, and the modern Echinacea hybrids display a rainbow of colors...red, orange, peach, etc.
There are nine Echinacea species that are distributed across the eastern and midwestern US in rocky open woods, barrens, meadows, roadsides, clear cuts, dry limestone bluffs, power line rights of way and prairies from New Mexico east to Florida, and north to Saskatchewan and Ottawa, Canada. The area of greatest species richness is in the grasslands of Oklahoma and Missouri. In general, coneflower plants prefer sunny sites with low levels of competition, plus high levels of magnesium and calcium. Periodic disturbance (fire, grazing, etc.) is necessary for the maintenance of their preferred open conditions. Echinacea is very drought tolerant and survives in places that receive as little as 15" of rain per year.
Echinacea purpurea was discovered in 1699 and by 1895, it was popular in European gardens as a medicinal herb and an ornamental flower. The Germans started improving Echinacea purpurea in the 1960s by making cultivar selections. The popularity of Echinacea purpurea started to surge in the 1980s and 1990s, especially after Echinacea purpurea 'Magnus' was awarded the 1998 Perennial Plant of the Year award from the Perennial Plant Association. Until 2003, most gardeners only grew the single-flowered, full-sized, purple-colored Echinacea purpurea. A few horticultural cognoscenti grew some white-flowered selections of Echinacea purpurea or the rare yellow-flowered species Echinacea paradoxa.
Then modern ornamental breeders got hold of Echinacea purpurea and blew the lid off of the genus. The Echinacea explosion started in 1997 when Jan van Winsen of Warmond, The Netherlands found a double-flowered seedling in his cut flower fields. It was the first of its kind in the world. After a marketing mis-start he passed it off to his friend, Marco van Noort, who successfully marketed it as 'Razzmatazz' in 2003. It was an immediate hit and lead to the breeding and release of many other double flowered purple coneflowers.
In 1968 Ronald McGregor published a monograph that first documented the possibility of interspecies crosses within the genus Echinacea, but it wasn't until 1995 that this information was put to the test when Dr. Jim Ault of the Chicago Botanic Garden selected this genus for his native plant breeding program. When I visited in 2003, I was dazzled to see the orange and pastel color combinations that Jim had created by mixing the yellow Echinacea paradoxa with the purple-flowered species. Around the same time, Richard Saul of Saul Nursery of Georgia began a program that echoed Jim's work, except that Richard based his program around Echinacea purpurea, while Jim's work was centered on Echinacea tennesseensis. As it turned out, the Echinacea purpurea hybrids made much better and longer-lived garden plants.
The next two Echinacea breeding programs to get cranked up were that of Terra Nova Nurseries in Oregon and of Arie Bloom in Holland. Terra Nova focused on more intense colors and Arie Blom's program focused on double-flowered forms. Additionally, everyone who has ever found a strange seedling in their garden has tried to bring their plant to market. This resulted in some truly ugly specimens such as the painfully deformed Echinacea 'Doppelganger'. Since 2003, there have been 5 or more new cultivars released every year, each with some breakthrough characteristic. There has rarely ever been an ornamental plant whose star has risen so fast. These breeders should be commended for their wonderful work. Plant Delights Nursery is happy to offer some of their best cultivars for sale and Juniper Level Botanic Garden displays many of these fine selections.
Echinacea purpurea is a perfect choice for a cut flower garden or a field-grown cut flower for fresh and dried flower markets because it has a large, long-lasting flower on a long, sturdy stem and is produced over a long period of time. The inflorescences remain open and colorful until they are pollinated, and then they fade and dry up without falling off. Modern hybrids often have reduced fertility or outright sterility which means that their flowers remain colorful longer than the wild types. In addition to its ornamental appeal, Echinacea attracts wildlife into the garden. The long lasting flowers are nectar sources for many flying insects including native bees, wasps, and butterflies. Additionally, the flowers serve as winter seed sources for many bird species, most notably the beautiful goldfinch.
Herbal Uses of Echinacea
Echinacea is not just a great garden plant; it is also widely used as an herbal medicine (primarily Echinacea angustifolia and Echinacea purpurea). Great Plains tribes of Native Americans such as the Sioux, Lakota, Omaha, Winnebago, Kiowa, Crow, Hidatsa, Comanche, Pawnee, Choctaw, Delaware and Cheyenne have used preparations of the roots for over 400 years as a general cure-all. Native Americans exposed European colonists to Echinacea and it was used widely during the 18th and 19th centuries to treat scarlet fever, syphilis, malaria, blood poisoning, and diphtheria.
Traditionally, Native Americans either chewed the pepper-flavored roots or they mashed the roots to apply them as a poultice. Today, people use extracts, ointments, pills, tablets or tinctures of the entire plant; roots, stems, leaves, and flower heads. It is popularly believed that Echinacea stimulates the immune system and reduces the length and severity of colds, flu, sore throats, coughs, fevers, and infections. However, clinical trials have been mixed; many have shown that it is effective but a few have shown that it is not. Some people swear by it, some totally reject it, and others are allergic to it. Echinacea was the most widely used plant remedy in the US and Europe until the dawn of the pharmaceutical age when it fell out of favor. In the last 25 years Echinacea has once again become a popular herbal remedy.
Echinacea is in the top ten for sales volume of herbs and botanicals in the US and represents 9% of the global herb market. Echinacea root prices swing wildly from $12 to $21 per pound. The global annual market for herbal formulations of Echinacea has been as high as $320 million in recent years. Farmers normally grow Echinacea purpurea for the herbal market because it is easy to cultivate, but the wild collectors prefer to harvest Echinacea angustifolia because it has thicker roots and a larger native range. Echinacea purpurea can be a difficult crop for farmers to financially justify because of the wildly fluctuating prices and multi-year production cycle.
There is evidence that Echinacea is allelopathic against some grass species. That is, it exudes a substance from its roots that inhibits the growth of nearby plants. There are no current applications of this property, but the commercial potential is being investigated. Echinacea angustifolia extracts have insecticidal properties and have the potential use as an organic insecticide.
Echinacea are deciduous herbaceous perennials, all of which have a taproot except for Echinacea purpurea. Echinacea form a slowly expanding clump that may be divided every few years to maintain vigor. The wild-type Echinacea are typically 2' wide and 3-4' tall. However, the high-plain taxa from Texas to Canada tend to be smaller than the eastern taxa. Modern hybrids have been selected for a smaller stature and range from less than 1 foot to 3' tall by 2' wide. In the wild, a single plant can live up to 40 years. In the garden, they are best when divided every 4 years.
Like all plants in the Asteraceae family, Echinacea flowers are actually inflorescences; a collection of 200-300 small fertile florets bunched together on the cone, known as disk florets. The disk florets are surrounded by a ring of sterile ray florets or what we refer to as petals. The entire inflorescence may be from 2" to 5" wide. The purpose of the ray florets is to attract pollinators with their bright colors to the disk florets where pollination occurs. If you look at a coneflower plant very carefully, you will note that the disk florets do not all shed pollen (reach anthesis) at the same time. The center disk florets open first, and proceed in an outward succession over the course of several days. You can watch this procession and use it to estimate how much longer your flower is going to live.
The disk florets may be dark burgundy, black, white, yellow or orange. The traditional color of Echinacea ray florets is pinkish-purple and less commonly yellow or white. However, modern hybrids have broken through this color barrier and petals can be found in shades of orange, peach, salmon, and reddish-orange. In wild-type echinacea, the petals may be held outward but are usually reflexed downward to varying degrees. The petals may be wide and overlap each other, but are more commonly narrow with space between them. Modern breeders have selected strongly for hybrids that have wide, overlapping, ray florets that are held outward. The wild-type Echinacea purpurea are often only lightly scented but Echinacea simulata and some of the modern hybrids are very sweetly scented.
The inflorescence is held on a strong, rigid, hirsute (hairy), usually unbranched stem (peduncle) that grows to 36" tall or more. The exception to the unbranched stems are cultivars such as Echinacea 'The King' and Echinacea 'Elton Knight', which have amazing widely-branched flower stalks. There may be small leaves spaced widely along the length of the flower stem. With many inflorescences produced in an overlapping sequence starting in July and continuing until frost. The overall effect is up to a dozen inflorescences that are open simultaneously.
How to grow Purple Coneflowers
Echinacea love hot, humid, sunny conditions. They are great plants for southern gardeners but are also quite cold tolerant. Most of the wild-types are hardy in zones 3-8 and can be grown almost anywhere in the continental US.
While Echinacea are well-adapted to nutrient-poor soils, you will get better performance out of your plants if you amend your soil with a well-draining compost. Wet soils in winter are sure to kill the newer hybrids, so plant them in well-drained soils or raised beds. Wild species grow in a variety of soil types including alkaline soil, dry sandy soil, glacial tills, fluvial silts, loess, clay, loam soils, and even coal mine spoils. They prefer a pH between 6 and 7. The wild species Echinacea angustifolia and Echinacea pallida can tolerate more alkaline conditions while Echinacea paradoxa and Echinacea tennesseensis prefer a more acidic soil. Echinacea are tough native plants that are quite drought tolerant once established in the garden. For best performance, however, we recommend at least 1-2" of water per week during the growing season.
Spent Echinacea flowers can be removed (dead-headed) to improve the general appearance of the plant, but it is not necessary. At the end of the season, leave the spent flowers on the plant and you will be rewarded with fall and winter visits by goldfinches who feed on the seeds.
How to Propagate Purple Coneflowers
Echinacea may be propagated by seed or division, but remember that hybrid cultivars will not come true from seed. All of the species are self-infertile to some degree. Gardeners who want their Echinacea to produce seed should plant at least 2 genetically distinct individuals. If the flower heads are not removed, the wild-types will re-seed in the garden. To grow Echinacea from seed, cut a stalk with a spent flower, enclose the flower in a paper bag and hang the plant upside down. The plant will release the seeds into the bag when they are ready. Separate the seeds from the chaff, dry them for a few weeks, and then store them in a cool dry place. The seeds are best when used in less than a year but they remain viable for at least 7 years. If you plan on storing them for a long time, the seeds should be refrigerated. Unfortunately, many of the new hybrid cultivars have reduced viability or are totally sterile.
It is unclear if Echinacea seed has a cold stratification requirement. Scientific studies have reported conflicting results. However, expert Echinacea breeder Dr. Jim Ault of the Chicago Botanic Garden gives his seeds 8 weeks of cold stratification. If sowing the seed indoors, surface-sow them in a pot at 68°F (20°C). Seed sown indoors or in a greenhouse germinate better than direct sown seed. To direct sow into the garden, plant the seeds ¼" deep and a few inches apart in the early spring. After germination, separate or thin the seedlings so that the plants are a minimum of 18" apart.
Clonal Echinacea will not come true from seed and are commercially propagated in tissue culture (micro cuttings taken in sterile lab conditions). New plants can be propagated by dividing established clumps. Dig around the clump, carefully lift it, and shake or wash off the soil. You should be able to divide the crown by hand but you may need a knife. There will be several rooted plants in each clump. Pull them apart and re-plant immediately. Remember that most of the new hybrids are patented, making their propagation illegal, although no one is going to mind if you divide plants for your own use.
There is anecdotal evidence that severed Echinacea taproots and fibrous roots can regenerate an entire plant. About 25%-50% of the plants that are hand dug for the herbal industry resprout the next year. All of the species except for Echinacea purpurea form a taproot and other thick fleshy roots and can be propagated via root cuttings. Place a pencil-sized piece of root upright (top side up) in a container in fall.
It is also possible to propagate Echinacea using basal stem cuttings. Take 4" to 6" cuttings in the spring and treat with 1000ppm powdered IBA. All commercial hybrids are propagated via tissue culture using axillary buds, stem cuttings, or individual cells.
Echinacea Pests and Diseases
In the garden, deer and other grazing animals will eat the young Echinacea plants but normally avoid mature plants, unless they are desperate. Echinacea can occasionally be infested by japanese beetles, root borers, aphids, cutworms, eriophyid mites, or tent caterpillars. The insects can be controlled with a number of commercial lures, traps, or pesticides.
Bacteria, phytoplasma, fungal, and viral diseases are rare but do occur. Occasionally, plants will get a fungal leaf spot (cercospora) that is ugly but will not kill the plant. Remove the affected leaves and throw them away (do not compost them). Some Echinacea cultivars are susceptible to powdery mildew (erysiphe), a white fungus present on the leaves that detracts from the overall appearance of the plant but is not fatal. Similarly, the plant may be infected with the fungus botrytis, which is also not fatal. Fungus diseases can usually be managed by growing the plants where they receive good aeration.
Wilt, blight, and root rot from fusarium or sclerotinia may also occur if the soils are kept too wet and the bacteria pseudomonas may cause brown leaf spots. Plants with any of these three diseases need to be removed and discarded as they can spread to other plants and are ultimately fatal.
On the other hand, virus and phytoplasma are generally spread by insects and, short of keeping your plants unstressed, are hard to prevent. The most fascinating is a phytoplasma (first cousin to a virus) disease called "aster-yellows" that will cause the central cones to mutate and sprout leaves and green flowers. The disease results in bizarre plants that everyone wants to introduce and patent when they should be pulling them up and throwing them away. Eventually the plants will die. The disease has a large host range, so gardeners should be vigilant about removing sick plants.
Native Echinacea species are dwindling in the wild from loss of habitat, slow re-colonization, and over-harvesting for the herbal industry. Despite the presence of many large herbal farms that grow echinacea, professional wild harvesters continue to indiscriminately harvest wild populations on private and public lands. Up to 200,000 lbs of Echinacea root are being harvested every year from the wild, faster than the species can regenerate. Echinacea species require the presence of frequent fires and large grazing mammals to maintain its open habitat. Modern ecological practices have greatly reduced the presence of grazing mammals in its native range and have all but eliminated natural fire ecology. Many man-made sites such as highway rights of way could support populations of echinacea, but they are too frequently cleared or treated with herbicides. Commercial, residential, or industrial development, road-building, intensive livestock grazing, and off-road vehicle use are other major sources of habitat destruction.
The name Echinacea comes from the Greek "echinos" meaning "hedgehog", which is a reference to the spiny center cone. The name Echinacea been used several times in the Linnaean classification system. There is a superorder within class Echinoidea of sea urchins called echinacea. There is also a species of moth called Coleophora echinacea. Oddly enough there is no hedgehog that uses this name.
Carl Linnaeus originally classified the plants as Rudbeckia purpurea in his seminal taxonomic reference Species Plantarum in 1753. In 1790, they were moved into their own genus called brauneria, but that name was quickly invalidated and they were moved back into rudbeckia. Then in 1794, the species Rudbeckia purpurea was separated from the genus rudbeckia and was given its own genus, echinacea, by Conrad Moench. Echinacea were also invalidly referred to as helichroa for a short time.
Echinacea are in the Asteraceae family (a.k.a Compositae). This is a huge plant family (currently 479 genera) that all have the same type of flower. Purple coneflowers are related to sunflowers (helianthus), daisies (leucanthemum), asters, mums (chrysanthemum), zinnias and many other " aster-like" plants. Taxonomists have not settled on the exact relationships between genera in the family Asteraceae, so the tribes and subtribes within the family are in a constant state of flux.
The number of species within the genus varied widely throughout its history, but in 1968 taxonomists finally settled on a list of nine species and four sub-species. The ubiquitous eastern purple coneflower is Echinacea purpurea. Others in the genus are narrow-leaf coneflower (Echinacea angustifolia), pale purple coneflower (Echinacea pallida), Tennessee coneflower (Echinacea tennesseensis), yellow coneflower (Echinacea paradoxa), Topeka purple coneflower (Echinacea atrorubens), smooth purple coneflower (Echinacea laevigata), wavy-leaf purple coneflower (Echinacea simulata), and sanguine purple coneflower (Echinacea sanguinea). Where their habitats overlap, the species readily interbreed, so there are many populations of naturally occurring interspecies crosses that have intermediate traits. In 2009, there were over 60 cultivars on the market and the number increases by every year.
Echinacea Cultivar Groups
The modern hybrid Echinacea are so new that no formal cultivar groups have been defined, nor have any interspecific hybrid names been designated (some nurseries have taken to using Echinacea hybrida but that name is not official). Based on the forms released since 2003, we can divide ornamental Echinacea into the following cultivar groups based on flower type, leaf color, and habit:
The wild-type Echinacea group consists of seed strain cultivars and clonal selections of individual species chosen for improved flower color, flower architecture or plant habit. Flower color varies from pale pink to a saturated pink/purple, or (rarely) white.
Double-flowered Echinacea hybrids
The double flowered hybrids may be any color including pink, purple, white, yellow, mango, or orange. The list of colors of double-flowered types expands every year. The flowers may be:
- anemone-formed (the disk florets are completely converted into small petals but the ray florets are unchanged)
- tufted (most of the disk florets are intact but the top of the cone contains a tuft of small petals)
- flower-over-flower (the disk florets are partially or completely converted into a new flower with its own ray florets and disk florets. The lower ray florets are unchanged)
- fully-double (the disk florets and ray florets are all petaloid and are all roughly the same size so that you cannot tell one from the other).
Novelty color Echinacea hybrids
The novelty color hybrids include all the new variants that have been created by breeding the purple-flowered species (pastel pink to saturated pink/purple, rose-pink, white) with Echinacea paradoxa (yellow). The array of novel colors is quite stunning and includes pastel to neon forms of yellow, orange, pink, purple, mango, coral, orange, salmon and all colors between. There is a green-flowered cultivar too. Breeders are filling in the color palette to cover the entire spectrum (except blue) and are extending the orange colors into new territory that borders on red. There is one cultivar, Echinacea ‘Green Envy’, that is even bicolored with pink and green petals.
Variegated Echinacea are rare. There are not many variegated forms of Echinacea on the market and the ones that are out there are not particularly vigorous. Variegation usually takes the form of white stippling on the leaves and is quite variable. Gardeners are anxiously awaiting the discovery of a stable, wide white edge or white center but none yet exist. Here at Plant Delights Nursery we have found a number of Echinacea with variegated foliage but so far they have been unstable and quickly reverted to green.
The dwarf group includes any plant under 24" in height. Breeders have selected many dwarf forms whose flowers are full-sized.
Novelty Echinacea flower architecture
The novelty flower type group currently contains only 1 stable selection. 'All that Jazz', from Kevin Hurd at Walters Gardens, has fluted petals that are rolled over in the middle much like a spoon-petaled osteospermum or gerbera.
The cultivar groups listed above highlight most of the traits that modern breeders are selecting for. They are extending the color palette, selecting for wide, erect petals, and double flowered plants. The new hybrids are often very sweetly scented. In addition, breeders are looking for hybrids that are easier to grow and more tolerate of wet conditions.
Echinacea Species and Cultivars
Echinacea angustifolia (Narrow Leaf Coneflower)
Echinacea angustifolia was not "officially" discovered by taxonomists until 1836, but in 1805 the explorers Louis and Clark sent Thomas Jefferson specimens of the plant from Fort Mandan during their famous exploration of the Louisiana Purchase lands. They referred to it as 'Mad Dog Plant' in their packing list, and state that it is "highly prized by the natives as an efficacious remedy in the cases of the bite of the rattle Snake or Mad Dog." This fantastic butterfly-attracting native, found from Canada south to Texas, is as stunning as Echinacea purpurea, just less known. The 30" tall stems are topped in late spring (mid-June) with large, attractive pink-purple heads, each composed of very narrow petals. Even if you don't like the looks of coneflowers (I can't imagine), Echinacea angustifolia is the most highly prized species for its medicinal properties...very popular among nursery owners. (Hardiness Zone 3-8)
Echinacea laevigata (Smooth Purple Coneflower)
Echinacea laevigata is a Federal Endangered species native from Pennsylvania south to Alabama. Like all echinaceas, it needs an open glade-like habitat and has become endangered due to forest fire suppressions...gee, thanks Smokey. Echinacea laevigata produces 3' tall flowers spikes with typical purple narrow petaled flowers. The leaves are never cordate, like other echinacea. (Hardiness Zone 3-8)
Echinacea pallida (Narrow Petal Coneflower)
This southeast native is kin to our commonly grown Echinacea purpurea, but with very narrow petals of pinkish purple atop 3' stalks in mid summer. Echinacea pallida is particularly useful in perennial borders due to its narrow form. (Hardiness Zone 5-8)
Echinacea paradoxa (Yellow Coneflower)
The difficult-to-find yellow coneflower is indeed a paradox as all other coneflowers are either purple or white. This strange relative from the Midwest (don't we all have one of those) has narrow, fuzzy green leaves that form a small basal clump which gives rise to 4'+ flower stems, topped in late spring with large yellow coneflowers with dark brown centers. (Hardiness Zone 4-9, possibly colder)
Echinacea purpurea (Purple Coneflower)
Without question, Echinacea purpurea has the most garden value as evidenced by the extraordinary number of commercial cultivars listed below. Because of its wide range in virtually every state East of the Mississippi River except Minnesota, it has a wide range of adaptability. (Hardiness Zone 3-9)
Echinacea purpurea 'Alba' (White Coneflower)
This is the commonly sold white-flowered seed strain of the purple coneflower. As with all seed strains, the plants are somewhat variable. (Hardiness Zone 3-9)
Echinacea purpurea 'Avalanche' PP 18,597 (Avalanche Coneflower)
Echinacea purpurea 'Avalanche' PP 18,597 is the best compact, single white-flowered coneflower in our trials. This 2006 Arie Blom hybrid makes a tight clump, adorned in summer with 20" tall spikes of large, white, horizontally-held petals...quite nice! (Hardiness Zone 3-9)
Echinacea purpurea 'Bright Star' (Bright Star Coneflower, syn: Echinacea purpurea 'Leuchstern')
This superb seed strain of our native coneflower is a bit taller than most (to 3-4') and has a slightly larger and more horizontally held rosy purple petals. (Hardiness Zone 3-9)
Echinacea purpurea 'Coconut Lime' PP 18,617 (Coconut Lime Coneflower)
This 2006 Arie Blom selection is topped with white, pompon style flowers with a hint of green. (Hardiness Zone 3-9)
Echinacea purpurea 'Cotton Candy' PPAF (Cotton Candy Coneflower)
This 2008 Arie Blom introduction makes a compact plant with 3' tall stems, topped with large double pink flowers, which we have found to rebloom well. (Hardiness Zone 3-9)
Echinacea purpurea 'Elton Knight' PP 18,133 (Elton Knight Coneflower)
From the UK's Anthony Brooks, gardener at Elton Hall, came Echinacea 'Elton Knight'. Echinacea 'Elton Knight' was one of only three coneflowers to receive the prestigious Award of Garden Merit in the Royal Horticultural Echinacea trials (2003). In our trials, Echinacea 'Elton Knight' stands apart not for its color, which is typical pinkish lavender, but for its sturdy 2' tall compact architectural habit and great branching. The flower stalks are topped in summer with 5" wide flower heads of nice outwardly held petals. Echinacea 'Elton Knight' is named for Thomas Andrew Knight, a founding member of the Royal Horticultural Society. (Hardiness Zone 3-9)
Echinacea purpurea 'Fatal Attraction' PP 18,429 (Fatal Attraction Coneflower)
This 2006 selection of our US native Echinacea purpurea is from Piet Oudolf's famed garden in Holland. Echinacea purpurea 'Fatal Attraction' PP 18,429 is unique because of the 26" tall sturdy wine black stems that hold the intense pink flowers...a favorite of garden visitors. Flowering begins in late June...be patient. (Hardiness Zone 3-9)
Echinacea purpurea 'Fragrant Angel' PP 16,054, PVR (Fragrant Angel Coneflower)
This sturdy 2004 release from Terra Nova Nurseries is the white counterpart of Echinacea purpurea 'Ruby Giant' and the best white coneflower we have ever grown. The giant 4-5" heads of pure white petals, around a contrasting orange cone, are also deliciously fragrant. Since these are clonally reproduced, each plant is identical for a more uniform planting. (Hardiness Zone 3-9)
Echinacea 'Green Envy' (Green Envy Coneflower)
When Mark Veeder first showed me a photo of his 2008 Echinacea purpurea seedling introduction; I thought for sure this was an April Fool's Photoshop™ creation. Only after growing and photographing the plant myself, can I say for sure, it is truly this unique. The 20" tall stems are topped, starting in mid-June, with large 4.5" wide flowers composed of a dark cone with a green center. Surrounding the cone, are long petals that are pink toward the cone changing to lime-green toward the downward recurving tips. Echinacea ‘Green Envy’ is so weird, gardeners will either love or hate it...we love it! (Hardiness Zone 3-9)
Echinacea purpurea 'Kim's Knee High' PP 12,242 (Kim's Knee High Coneflower)
From Tony's college classmate Kim Hawks, former owner of Niche Gardens, comes a 1999 dwarf selection of the wonderful native purple coneflower. This compact selection is the first coneflower to be vegetatively propagated, ensuring that every plant is identical...no seed-grown variation as long as you remove the old seed heads. Starting in mid-June (NC), each flower head has rigidly reflexed, rosy-pink petals that give a truly unique look to this selection. (Hardiness Zone 3-9)
Echinacea purpurea 'Kim's Mop Head' PP 13,560 (Kim's Mop Head Coneflower)
Echinacea 'Kim's Mop Head' is a 2001 introduction and is the white flowered companion to Echinacea purpurea ‘Kim’s Knee High’. This mutation of Echinacea purpurea ‘Kim’s Knee High’, discovered at Sunny Border Nursery in Connecticut, has the same wonderful compact habit with perfectly symmetrical downward arching heads of fringed-white petals. (Hardiness Zone 3-9)
Echinacea purpurea 'Kim's Red Knee High' PP 20,411 (Kim's Red Knee High Coneflower)
Echinacea purpurea 'Kim's Red Knee High' PP 20,411 is a mutation of Echinacea purpurea ‘Kim’s Knee High’ PP 12,242, discovered at Connecticut's Sunny Border Nursery in 2005. Echinacea purpurea 'Kim's Red Knee High' PP 20,411 has the same vigorous growth, short habit and attractively reflexed petals of its parent. The name red, however, is problematic...another example of male color-blindness and why you never ask men to describe a color. The color is actually a richer, darker pink than the parent, but nothing close to red. (Hardiness Zone 4-9)
Echinacea purpurea 'Lilliput' PP 18,841 (Lilliput Coneflower)
From the Terra Nova breeding program in 2006 came one of the most compact of the dwarf coneflowers that we have seen. The tight clumps are adorned, starting in early summer, with 16" tall flower spikes of large, fragrant, rosy-pink flower heads...perfect for the front of the border. (Hardiness Zone 4-9)
Echinacea purpurea 'Little Giant' PP 16,183 (Little Giant Coneflower)
This 2004 Terra Nova selection of our native Echinacea purpurea combines the large 4-5" wide flowers and flat petal arrangement of Echinacea purpurea 'Ruby Giant' with a compact habit. Each 16" tall clump is topped with the large fragrant pink flowers starting in early summer. For smaller planting spaces, Echinacea 'Little Giant' just what the plant doctor ordered. (Hardiness Zone 4-9)
Echinacea purpurea 'Magnus' (Magnus Coneflower)
This seed strain of our US native was selected by Sweden's Magnus Nilsson for its vibrant pinkish purple color and strongly horizontal petal formation and was named the 1998 Perennial Plant of the Year. In spring, the small rosettes of narrow green leaves unfurl, then are topped in midsummer by 30" spikes ending in 3-4" wide purple petaled, black-eyed Susan-type flowers. (Hardiness Zone 3-10)
Echinacea purpurea 'Meringue' PP 20,537 (Meringue Coneflower)
This 2008 Arie Blom introduction is a compact 16" tall version of their Echinacea 'Coconut Lime' with double white pompom flowers. (Hardiness Zone 3-9)
Echinacea purpurea 'Milkshake' PP 20594 (Milkshake Coneflower)
This coneflower from Holland's Arie Blom has made a real splash in our trials. The amazing branched flower spikes are composed of large, double, white flowers, each surrounded by a row of single petals. For us, Echinacea purpurea 'Milkshake' starts flowering in midsummer and re-blooms in the fall. Although the breeder claims a 3' tall flower stem, our plants have never topped 2' tall. (Hardiness Zone 4-9)
Echinacea purpurea 'Pink Double Delight' PP 18,803 (Pink Double Delight Coneflower)
The 2006 introduction has impressed us with its excellent performance in our trials. Developed by Arie Blom of the Netherlands, this vigorous and floriferous cultivar is composed of sturdy 24" tall stems, each topped with double flowers starting in July and continuing until frost. Each flower head is composed of an oversized, dark pink cone adorned with lighter pink petals. Echinacea 'Pink Double Delight' needs 8+ hours of full sun to prevent the maturing flowers from doing a Greg Louganis half gainer. (Hardiness Zone 3-9)
Echinacea purpurea 'Pink Poodle' PPAF (Pink Poodle Coneflower)
Echinacea purpurea 'Pink Poodle' PPAF from the Terra Nova breeding program is the latest (2008) in the line of double-flowered pink coneflowers. Echinacea purpurea 'Pink Poodle' PPAF boasts rounded, double pink flowers that look like one of those overly-clipped poodle tails, atop well-branched, sturdy 3' tall stems in the summer months...at least they've bred out that incessant yapping from its namesake. We find that the first few flowers may be a bit deformed until the plants gets settled into the garden. (Hardiness Zone 3-9)
Echinacea purpurea 'Purity' PP 19,441 (Purity Coneflower)
This 2007 Terra Nova hybrid is a descendant of Echinacea purpurea 'Fragrant Angel’ and another new advance in white-flowered coneflowers. Echinacea 'Purity' offers a well-branched, architecturally sturdy 26" tall plant, topped in mid-summer with 4.5" wide pure white flowers. (Hardiness Zone 4-9)
Echinacea purpurea 'Razzmatazz' PP 13,894 (Razzmatazz Coneflower)
From Holland's Jan van Winsen comes this stunning Echinacea purpurea seedling (from Echinacea 'Magnus') that appeared in his fields in 1997. The unique, double pompom flower atop 30" stems makes this one of those rare plants that elicit "oohs" and "ahhs" from those who see the plant in flower or merely in a photograph. Since the flower heads are heavier than normal, we recommend an area with bright light and good air movement, which will strengthen the stems. This is the first of the double-flowered coneflowers to hit the market. (Hardiness Zone 3-9)
Echinacea purpurea 'Ruby Giant' (Ruby Giant Coneflower)
This Dan Heims selection of the US native Echinacea purpurea is from the European garden of the son of Magnus Nilsson (Echinacea 'Magnus'). This clump was selected from the parent stock for the seed strain Echinacea 'Rubinsturn'. One particularly nice plant was selected for vegetative propagation...all offspring are now identical. Echinacea purpurea 'Ruby Giant' boasts large 5-7" wide flowers of pure bright clear pink, each with upcurved petal tips. Did I mention the flowers are delightfully fragrant? This is truly a stunning selection that is a must for every border! (Hardiness Zone 3-9)
Echinacea purpurea 'Sparkler' PP 17,298 (Sparkler Coneflower)
Echinacea 'Sparkler' is a truly unique 2005 sport of Echinacea purpurea 'Ruby Giant' that forms a nice, dwarf, compact clump to only 26" tall by 18" wide. The green leaves emerge frosted white and hold this pattern until very hot weather arrives. Each clump is topped with 26" tall flower spikes of 4" wide fragrant, light-pink flowers. If you enjoy plants with variegation, this one's for you. (Hardiness Zone 3-9)
Echinacea purpurea 'The King' (The King Coneflower)
This UK selection was the first clone to show wide horizontal branching on the flower stem. Its pollen was used to produce a more compact variety with the same branching, that was introduced as E. 'Elton Knight'. The flat-petaled 5-6" wide flowers are the typical Echinacea purpurea color. (Hardiness Zone 3-9)
Echinacea purpurea 'Vintage Wine' PP 13,893 (Vintage Wine Coneflower)
This introduction of our US native comes from Holland's designer extraordinaire, Piet Oudolf. Echinacea 'Vintage Wine' in Piet's garden as a self-sown seedling in a patch of Echinacea purpurea. It was selected for its 2' tall, sturdy, upright habit and branched flower stems. The flat but short outfacing petals of a unique wine-pink (RHS 63A) color are darker toward the tip and top the plant from July through September. (Hardiness Zone 4-9)
Echinacea purpurea 'Virgin' PP 18,684 (Virgin Coneflower)
This 2006 coneflower introduction comes from Netherlands garden designer, Piet Oudolf. The compact clumps are topped in summer with sturdy 2' stems, ending in an abundance of 4" wide flowers composed of a fragrant dark green cone and surrounded by frilly-white petals. (Hardiness Zone 4-9)
Echinacea purpurea 'White Swan' (White Swan Coneflower)
The seed strain is considered the best of the non-clonal whites, producing flowers atop sturdy 18" stems. (Hardiness Zone 3-9)
Echinacea simulata (Wavy-leaf Purple Coneflower)
Echinacea simulata is very similar to Echinacea pallida except that the pollen is yellow instead of white. The leaves are very narrow and the flowers have reflexed, narrow purple petals. (Hardiness Zone 5-8, at least)
Echinacea tennesseensis (Tennessee Coneflower)
Echinacea tennesseensis is another federally endangered species, which means you must obtain permits in order to sell it. Consequently, it is sold as Echinacea 'Rocky Top', since the folks in charge of enforcing stupid Endangered Species regulations think that once you give the plant a cultivar name then it is no longer endangered....here's your sign. This wonderful species, native to the cedar glades of three counties in central Tennessee, was thought to be extinct until the '60s when it was rediscovered. Echinacea tennesseensis makes a robust clump of narrow leaves, topped with 2' tall flower spikes ending in bright pink flower heads of narrow, slightly upturned petals. Echinacea tennesseensis is one of the longest lived and most adaptable of the coneflower family...provided it has very good drainage. (Hardiness Zone 5-8)
Echinacea Hybrid Cultivars
Echinacea 'Adam Saul' PP 21023 (Crazy Pink Coneflower)
This 2008 introduction from Itsaul Plants forms a 2' tall by 2' wide clump with over 100 flowers per plant, making it one of the most floriferous echinacea on the market. The flowers, which start in early summer, are typical pink with reflexed petals. (Hardiness Zone 4-9)
Echinacea 'Art's Pride' PP 15,090 (Art's Pride Coneflower)
Calling Echinacea 'Art's Pride' a breakthrough was like calling Ted Kennedy a bit left of center. This amazing 2003 release comes from the breeding program of Dr. Jim Ault of the Chicago Botanic Garden and was the first of the orange-flowered coneflower hybrids. Each 2' wide clump of slender green foliage is topped starting in late June and continuing through the summer with 30" bouquet-like spikes of rustic-orange flowers. Unfortunately, it made a poor garden specimen. (Hardiness Zone 4-8)
Echinacea 'Coral Reef' PPAF (Coral Reef Coneflower)
This wild and crazy 2009 Terra Nova introduction produces large pompon-like flowers of peachy orange, each surrounded by a small row of peachy petals. The clusters of flowers are borne atop 3' tall stems starting in mid-June (NC). (Hardiness Zone 4-9)
Echinacea 'Evan Saul' PP 17,659 (Evan Saul Coneflower)
This 2005 coneflower from Richard Saul (named after his son) arises in spring as a basal rosette of narrow green leaves from which rise sturdy 40" tall stems. Starting in June, the flowering stems are topped with 3.5" bright orange flowers that have a delightfully sweet aroma. This F3 hybrid of Echinacea purpurea and Echinacea paradoxa (lots of good inbreeding...popular down there in the Georgia mountains) makes a fast-growing clump which, under good conditions, will produce 60 flowers on a one-year-old plant. (Hardiness Zone 4-9)
Echinacea 'Firebird' PPAF (Firebird Coneflower)
This 2009 release from Terra Nova Nurseries makes a nice compact clump, topped, starting in early summer, with 3' tall spikes of flowers composed of bright reddish-orange reflexed petals surrounding a dark brown central cone. (Hardiness Zone 4-9)
Echinacea 'Flame Thrower' PPAF (Flame Thrower Coneflower)
Echinacea 'Flame Thrower' PPAF is a 2009 Terra Nova introduction with 40" branched stalks, topped, starting in early summer, with fragrant, bright orange flowers. The narrow, flat petals are light orange near the recurving tips and darken toward the central orange cone...very floriferous! (Hardiness Zone 4-9)
Echinacea 'Heavenly Dream' PPAF (Heavenly Dream Coneflower)
Echinacea 'Heavenly Dream' is a Terra Nova release with 4" wide white flowers. (Hardiness Zone 4-9)
Echinacea 'Hot Lava' PPAF (Hot Lava Coneflower)
Echinacea 'Hot Lava' PPAF is another 2009 hybrid from the Terra Nova breeding program. The sturdy 4' tall stems are topped, starting in midsummer, with wide-petaled, orange-coned bright reddish-orange flowers...quite stunning. (Hardiness Zone 4-9)
Echinacea 'Hot Papaya' PPAF (Hot Papaya Coneflower)
This 2009 echinacea breakthrough comes from Holland's Arie Blom. The vigorous 3' tall stalks of Echinacea 'Hot Papaya' PPAF are topped through the summer with an amazing display of lightly fragrant, bright orange pom poms, surrounded by a row of single drooping petals. (Hardiness Zone 4-9)
Echinacea 'Katie Saul' PP 18,783 (Katie Saul Coneflower)
From Georgia's Saul Brothers comes their 2006 release, which forms a clump of 3' tall dark stems, each topped, starting in midsummer, with 5" wide, uniquely colored flowers that are peach toward the tips but change to cherry red near the central cone. The effect is a bicolor flower, which gives rise to all kinds of garden color combinations. (Hardiness Zone 4-9)
Echinacea 'Little Angel' PPAF (Little Angel Coneflower)
This 2010 Terra Nova introduction is a 16" tall compact, reblooming coneflower with open, reflexed white petals. (Hardiness Zone 4-9)
Echinacea 'Mac 'n' Cheese' PP 19,464 (Mac 'n' Cheese Coneflower)
From hot off the stove, we are pleased to serve up this cheesy 2009 Terra Nova introduction. Echinacea 'Mac 'n' Cheese' PP 19,464 boasts a compact, well-branched habit, topped with 4"+ yellow-orange flowers, starting in mid-June (NC) on 26" stems. (Hardiness Zone 4-9)
Echinacea 'Mango Meadowbrite' PP 16,636 (Mango Meadowbrite Coneflower,
syn: Echinacea CBG Cone3) This dazzling 2004 coneflower from the breakthrough breeding work of Dr. Jim Ault of the Chicago Botanic Garden created yet another color in coneflowers. Echinacea 'Mango Meadowbrite' PP 16,636 is topped with 3" wide, mango-colored (RHS 21A), fragrant flower heads surrounding a slightly darker orange central cone. Actually, the color is closer to orange-mustard, but that doesn't sound quite as appealing. This is a stunning plant in flower that is sure to stand out in the garden. It was named Echinacea 'CBG Cone3', which is an invalid cultivar name, so we renamed it Echinacea 'Mango Meadowbrite' PP 16,636. (Hardiness, Zone 5-8)
Echinacea 'Matthew Saul' PP 17,652 (Matthew Saul Coneflower)
This 2005 release from Georgia's Saul Brothers is topped starting in July with lovely, 4" wide, peachy-orange flowers surrounding an orange central cone atop 30" tall stems. Echinacea 'Matthew Saul' PP 17,652 is a delightful new color break in the genus, not to mention lightly fragrant. (Hardiness Zone 4-9)
Echinacea 'Paranoia' PP 16,587 (Paranoia Coneflower)
Richard Saul of Itsaul Plants in Georgia made some echinacea crosses in the mid-'90s (Echinacea paradoxa x purpurea) and passed along seed to us. We selected Echinacea 'Paranoia' PP 16,587 as the star, due to its compact 10" tall by 1' wide growth habit and lovely rigid yellow flowers, and introduced it in 2004. This is unfortunately not the easiest coneflower to maintain in the garden due to its lack of vigor. (Hardiness Zone 5-8)
Echinacea 'Pixie Meadowbrite' PP 18,546 (Pixie Meadowbrite Coneflower
, syn: Echinacea 'CBG Cone 2') Echinacea 'Pixie Meadowbrite' PP 18,546 is a 2006 release, and the third from Dr. Jim Ault's breeding program at the Chicago Botanic Garden. This new coneflower is the result of an intentional horticultural menage-a-trois with Echinacea purpurea, tennesseensis, and angustifolia. The result is a charming 18" tall by 2' wide compact clump, composed of sturdy flowering stems that end in mid-sized, flat-petaled pink flowers that rebloom all summer...a real winner! Since it was given the illegitimate name of CBG Cone 2, we have renamed it using their illegal trademark name of Echinacea 'Pixie Meadowbrite' PP 18,546 as the cultivar name. (Hardiness Zone 4-9)
Echinacea 'Sunrise' PP 16,235 (Sunrise Coneflower)
This 2005 introduction from plantsman Richard Saul of GA was the first of the yellow-flowered hybrids. This cross of Echinacea purpurea x Echinacea paradoxa makes a 2' tall by 2' wide clump, topped in summer with 4" fragrant, buttery-yellow flowers that age to creamy white. Echinacea 'Sunrise' PP 16,235 has proven to be a very sturdy plant and a good rebloomer...more color for the summer and early fall garden! (Hardiness Zone 3-8)
Echinacea 'Sunset' PP 16,424 (Sunset Coneflower)
This 2005 coneflower from Richard Saul of Itsaul Plants combines the best of Echinacea purpurea and Echinacea paradoxa into a selection that is topped, starting in June, with large 4.5 - 5" wide fragrant heads of bright orange, fragrant blooms on 30" stems. The lush basal rosette of wide green foliage and dark flower stems serve as a nice foil to the prolific flower display...thanks to an abundance of side-flower buds. In cool climates, the flowers may have a unique lavender cast as they age. (Hardiness Zone 4-8)
Echinacea 'Tangerine Dream' PPAF (Tangerine Dream Coneflower)
Echinacea 'Tangerine Dream' PPAF is a 2009 Terra Nova introduction that sports well-branched 30" stems of large, 4", sweetly fragrant, bright orange, non-fading flowers...what more could you ask for a summer-flowering perennial? (Hardiness Zone 4-8)
Echinacea 'Tiki Torch' PP 18,839 (Tiki Torch Coneflower)
This dynamite 2006 echinacea introduction comes from the breeding program at Oregon's Terra Nova Nurseries. The 32" branched stems are topped with multitudes of pumpkin-orange flowers starting in late June...a fabulous new color! (Hardiness Zone 4-9)
Echinacea 'Tomato Soup' PP 19,427 (Tomato Soup Coneflower)
This 2009 echinacea from Terra Nova indeed stretches what we used to think about coneflowers to an entirely new level. The 32" tall clumps are topped in summer with large 5" flowers, whose petals indeed look like the color of mama's tomato soup. It's a shame the late Christopher Lloyd isn't still around to create some of his renowned, stirring combinations with this wild and gaudy color. (Hardiness Zone 4-9)
Purple coneflowers are admirable and dependable American native plants for any garden. This perennial wildflower brings dazzling beauty to sunny gardens with its showy flowers. Purple coneflower can be grown in all 48 contiguous states and even in southern Alaska. We hope you've enjoyed our summary of this amazing genus of plants and will now explore their wonderful garden potential in your own garden....in other words, become a conehead!
AB Cultivars web site, http://www.ab-cultivars.com
Adam, K.L., (2002), Echinacea as an Alternative Crop: Horticulture Technical Note, TTRA - National Sustainable Agriculture Information Service
Arnold, J.E. et. al., Efforts to Save an Endangered Species -Echinacea laevigata (Smooth Coneflower), http://virtual.clemson.edu/groups/hort/sctop/pdf_docs/bsec/bsec-13.pdf
Ault, J., (2002), Echinacea Evolution, NMPro Magazine, November 2002, 18(11):34-36.
Ault, J., (2007), Coneflower: Echinacea species, In: Flower Breeding and Genetics: Issues, Challenges and Opportunities for the 21st Century, 1st Edition, Neil Anderson, Editor, Springer Publishing, pp. 801-822.
Bachman, J., (2006), Specialty Cut Flower Production and Marketing, ATTRA - National Sustainable Agriculture Information Service, http://attra.ncat.org/attra-pub/PDF/cutflower.pdf
Backyard Nature, Echinacea (Purple Coneflower) Flowers, http://www.backyardnature.net/fl_echin.htm
Balge, R. et. al., Production of Purple Coneflower as a Cut Flower, Maryland Cooperative Extension Fact Sheet FS371
Blessington, T.M., et. al., Echinacea Production and Consumer Care, Maryland Cooperative Extension Leaftlet #EH401
The Center for Plant Conservation, (2009), Echinacea laevigata, CPC National Collection Plant Profile, http://www.centerforplantconservation.org/collection/CPC_ViewProfile.asp?CPCNum=1541
The Convention on International Trade in Endangered Species (CITES), http://www.cites.org/, and http://www.cites.org/eng/app/appendices.shtml
Cox, P.B., & Urbatsch, L.E., (1990), A Phylogenetic Analysis of the Coneflower Genera (Asteraceae: Helianthae), Systematic Botany, 15(3), pp. 394-402
Encyclopedia of Life, Echinacea, http://www.eol.org/pages/59379
Clark, W. (1804), Fort Mandan Packing List, Box 4, http://www.monticello.org/education/lcresource/ftmandanlist.html
Frett, J., and Piatt, V., (2009), Coneflowers for the Mid-Atlantic Region, Mt. Cuba Center Research Report
Flynn, P., (1998), Yellows Disease of Purple Coneflower, Iowa State University Extension Horticulture and Home Pest News, http://www.ipm.iastate.edu/ipm/hortnews/1998/7-24-1998/yellows.html
Gilman, E.F., (1999), Echinacea purpurea, University of Florida Cooperative Extension Service Fact Sheet FPS-192
Groen, Amy H. 2005. Echinacea angustifolia. In: Fire Effects Information System, U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory http://www.fs.fed.us/database/feis/plants/forb/echang/all.html
Gruenwald, J., (2008), The Global Herbs & Botanicals Market, Nutraceuticals World, July/August 2008.
Hatch, P., (2003), "Public Treasures": Thomas Jefferson and the Garden Plants of Lewis and Clark, Twinleaf Journal, January 2003 issue
Hawks, K., (2004), Coneflowers: An American Classic, The American Gardener, American Horticultural Society.
Hobbs, C. (1998), Echinacea: From Native American Panacea to Modern Phytopharmaceutical, http://www.christopherhobbs.com/website/library/articles/article_files/echinacea_01.html
Kemper Center for Home Gardening, (2001), Missouri Botanical Garden
Kindscher, K., Ed. (2006), The Conservation Status of Echinacea Species, Kansas Biological Survey
Louis and Clark Expedition Journals, 16th December, Sunday 1804 and 28th February Thursday 1805, http://lewisandclarkjournals.unl.edu/read/?_xmlsrc=1804-12-16.xml&_xslsrc=LCstyles.xsl, and http://lewisandclarkjournals.unl.edu/read/?_xmlsrc=1805-02-28.xml&_xslsrc=LCstyles.xsl
McGregor, R.L. 1968. The taxonomy of the genus Echinacea (Compositae). The University Kansas Scientific Bulletin 48(4): pp. 113-142.
McIntire-Strasburg, J., (2008), Herbs for Health: Endangered Echinacea, in sustainablog., http://blog.sustainablog.org/herbs-for-health-endangered-echinacea/
McKeown, K.A. (1999). A review of the taxonomy of the genus Echinacea. p. 482-489. In: J. Janick (ed.), Perspectives on new crops and new uses. ASHS Press, Alexandria, VA. http://www.hort.purdue.edu/newcrop/proceedings1999/v4-482.html
Miller, S.C., & Yu, H. (2004), Echinacea: The genus Echinacea, CRC Press
Mussulman, J. (2003), Legends; on the Discovering Louis and Clark web site, http://lewis-clark.org/content/content-article.asp?ArticleID=1399
North Carolina Native Plant Society, http://www.ncwildflower.org/guidelines.htm
Rice, G. (2007), A New Dawn for Echinacea, The Plantsman, Dec 2007
Rogers, D. H., Echinacea angustifolia D.C.: Blacksamson Echinacea, Smithsonian Museum of Natural History, http://www.mnh.si.edu/lewisandclark/resources/Echinacea_angustifolia.pdf
Schoellhorn, R. (2004), Echinacea - Celebrate Diversity, Greenhouse Product News, 14(11), http://gpnmag.com/Echinacea-Celebrate-Diversity-article5607
Schoellhorn, R. & Richardson, A.A., Warm Climate Production Guidelines for Echinacea, University of Florida Leaflet ENHFL04-008
Thomas Jefferson Encyclopedia; Entry for: Purple Coneflower, http://wiki.monticello.org/mediawiki/index.php/Purple_Coneflower
University of Illinois, Diseases of Echinacea sp. (Coneflower), Focus on Plant Problems, http://urbanext.illinois.edu/focus/per_echinacea.cfm
University of Maryland Medical Center (2007), Echinacea overview, http://www.umm.edu/altmed/articles/echinacea-000239.htm
Urbatsch, L.E., et. al., (), 272. Echinacea Moench, Methodus. 591. 1794, Flora of North America, Vol 21, Pg 43, 64, 65, 88, http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=111203
USDA NCRS Plant Guide, Purple Coneflower, http://plants.usda.gov/plantguide/pdf/cs_ecan2.pdf
USDA PLANTS database, http://plants.usda.gov/java/profile?symbol=ECHIN
U.S. Fish and Wildlife Service, Endangered species program,