Narrow Leaf Purple Coneflower
(Echinacea angustifolia DC.)

botanical information

Echinacea angustifolia DC. is an herbaceous perennial and a member of the Asteraceae family.  Commonly called narrow leaf purple coneflower, it has a natural range in North America that includes most of the mid-western states east of the Rocky Mountains.  E. angustifolia grows at a rate of six to eight inches a year to a mature height of twelve to twenty-eight inches.  The leaves are lanceolate to linear-lanceolate, and the flowers are cone-shaped disks with purple, pale pink, or rarely white spreading ray flowers.  The plant has one or more stems that are mostly unbranched, and flowers bloom from June to July.  The taproot of cultivated E. angustifolia is harvested three-to-four years from seed.  It is the root that is believed to contain most of the plant’s medicinal value, although the herb is also used.  

medicinal uses

E. angustifolia has a long tradition of use among the native people of North America.  It continues to be the most widely used herbal remedy in native cultures.  In modern cultures of North America and Europe, E. angustifolia is primarily used in medicines believed to stimulate the immune system.  Of the three Echinacea species used for medicinal purposes (E. purpurea, E. angustifolia, and E. pallida), E. angustifolia is regarded as the most chemically active possessing anti-bacterial, anti-viral and anti-fungal properties.  Traditional/folk uses include a blood purifier, fevers, acne, and to treat infections and sores.  

selecting a planting site

E. angustifolia can be grown almost anywhere within the temperate zones and is quite cold hardy.  Echinacea prefers a well-drained alkaline soil in a sunny location.  Recommendations for pH range from 6.0 to 7.5.  E. angustifolia can tolerate hot and dry conditions but extensive drought can reduce size and yields.  Raised beds are highly recommended, especially for moist or clay soils.  Poorly drained soils should be avoided.

planting

Propagation of E. angustifolia can be from seed or transplants.  While division of the crown is one option for propagating E. purpurea, it is more difficult with E. angustifolia due to its taproot.  Seed germination is also more difficult, often yielding only 50% germination rates.  Johnny’s Selected Seed Co., Winslow, Maine, recommends the following guidelines for starting seeds indoors.  Echinacea species require light and cold stratification (pre-chilling) for seed germination.  Using deep containers to allow for good root development, fill with a prepared soil mix, and plant seeds in flats or pots, barely covering the seed with soil.  Moisten, cover, and refrigerate at 40-50⁰F.  E. angustifolia requires at least twenty-one days of cold stratification. After stratifying, expose flats or pots to warmer temperatures to allow for emergence of the seedlings.  Germination generally occurs ten to twenty days after the stratification process. 

 When plants are several inches tall (usually eight to twelve weeks after germination), transplant seedlings in well-prepared, permanent, planting beds, late spring or early summer.  Space plants eight to fifteen inches apart, making rows eighteen to thirty inches apart.  The taproot allows for closer spacing in the field.  Weed control is very important, as echinacea does not compete well with weeds.  Plants will benefit from the use of mulch. 

 Seeds can be sown directly in the ground in fall or early spring, but a fine seedbed needs to be prepared.  Plant seeds just under the soil surface spacing them two inches apart.  Keep bed moist and weed-free.  When seedlings emerge, thin to the recommended spacing mentioned above.  

insects and diseases

Diseases that affect echinacea include the leaf spots Cercospora rudbeckii and Septoria lepachydis and can cause blackening of the leaves.  A root rot, Phymatotrichum omnivorum, has also been identified.  Another disease called “aster yellows disease” is a virus that is transmitted by a leafhopper feeding on echinacea.  Other insects that feed on echinacea include Japanese beetles and thrips. 

harvesting, cleaning, and drying

Echinacea root is harvested in the fall after the plant has gone dormant, usually the second to fourth growing season, depending on which planting method is used - direct seeding or transplanting.  A spading fork or other digging tool can be used as well as a modified potato digger.  As roots are pulled out of the planting beds, be careful to not damage or break the taproot.  Shake the roots free of dirt and carefully remove only roots that are echinacea.  Put plants in the shade until harvesting is complete.  When ready for processing, it is recommended to wash echinacea roots with a pressure hose.  Richo Cech, author of Growing At-Risk Medicinal Herbs, recommends processing the echinacea as soon as possible after washing to minimize oxidation.

 Once the roots are cleaned, spread on non-aluminum screens for the drying process.  E. angustifolia roots can be dried whole.  They need a warm location with adequate airflow.  If a drying unit is not available, a large dehydrator, converted greenhouse, or converted rooms in a barn are areas that can be used for drying.  According to Cech, “Dry for one day at 70⁰F, then turn the temperature up to 110⁰F, drying the roots until they snap.”  Cech recommends, “storing the dried root in plastic bags in light-proof sacks or drums, in a cool, dark, and dry location for up to one year.”  Yield estimates after three growing seasons average 1125 pounds of dried root.

markets  

E. angustifolia is traded at a higher price than the other two species used as a medicinal.  Most of E. angustifolia on the market is wild-harvested, and populations are declining.  Demand for cultivated E. angustifolia will depend on its ability to produce the same bioactive content as wild-harvested material.  Echinacea has a worldwide customer base consisting of large, medium and small processors.  Many medium-to-large buyers are not interested in paying a premium price for this material since the products they produce do not differentiate the species from the genus.  A few buyers are beginning to endorse E. angustifolia as superior to E. purpurea to distinguish their company’s products from other companies.

 According to ATTRA, National Sustainable Agriculture Information Service, in many states, conservation measures have been passed to protect native populations of the Echinacea species.  Cultivation of all species is to be encouraged.  E. angustifolia is currently being cultivated in the United States, Canada, Australia, New Zealand, Chile, and Costa Rica.  The challenge to medicinal herb growers is finding a reliable source of seed true to the particular species, since echinacea can cross-pollinate easily.  Growers should buy from a reliable seed source that specializes in selling seed for the medicinal herb industry.

Adam, Katherine L. 2002. Echinacea as an alternative crop. ATTRA - National Sustainable Agriculture Information Service. Click here for Web site. 14 pp.

Cech, Richo. 2002. Growing At-Risk Medicinal Herbs. Horizon Herbs. Williams, Oregon. 314 pp.

 Fernald, M. L. 1970. Gray’s Manual of Botany. D. Van Nostrand Company, New York, NY. 1632 pp.

 Greenfield, Jackie, and Jeanine M. Davis. 2004. Medicinal herb production guides. North Carolina State University, Raleigh, NC.

 Hwang, Sheau-Fang, Chang, Kan-Fa, and Ron Howard. 2001. Yellows diseases of echinacea, monarda, and caraway. Agriculture, Food and Rural Development. Crown copyright. Alberta, Canada. 6 pp. Click here for Web site.

Jensen, Beth. 2004. Johnny’s Selected Seeds. Winslow, Maine. Personal communication.

 Strategic Reports. 2002. Analysis of the economic viability of cultivating selected botanicals in North Carolina. A report commissioned for the North Carolina Consortium on Natural Medicinal Products by North Carolina State University, Raleigh, NC. 244 pp.

 Sturdivant, Lee, and Tim Blakley. 1999. Medicinal Herbs in the Garden, Field, and Marketplace. San Juan Naturals. Friday Harbor, Washington. 323 pp.

 US Department of Agriculture, Crops Research Division Agricultural Research Service. 1960. Index of Plant Diseases in the United States, Agriculture Handbook No. 165. Washington, DC. 531pp.

 Westcott, Cynthia. 1960. Plant Disease Handbook. D.Van Nostrand Company, Inc. Princeton, NJ. 825 pp.

The North Carolina Arboretum is grateful to Jackie Greenfield and Jeanine M. Davis for their contributions to this publication, including excerpts from their publication “Medicinal Herb Production Guides”. The Arboretum also wishes to thank Richard Rice for his artistic renditions of the herbs. The Superb Herbs Web site and the documents provided were made possible by a grant from the NC Department of Agriculture and Consumer Services, found on the Web at www.ncagr.com.