Valerian (Valeriana officinalis L.)

botanical information

Valeriana officinalis L. is a hardy herbaceous perennial, native to Europe and northern Asia, and is a member of the Valerianaceae family.  Commonly called Valerian, it has escaped from cultivation and naturalized from northeastern United States to New Jersey, Ohio, Pennsylvania, and from Quebec to Minnesota.  It often grows to a height of four to five feet and can reach up to six and one-half feet.  The leaves are pinnate, opposite, and deeply divided.  The leaflets are in pairs and are lanceolate-acuminate.  The small pink to white flowers form clusters and bloom from June to September.  The plant self-seeds easily and gives off a peculiar odor.  It is the root that is used for medicinal purposes, and the rhizome and roots are usually harvested in fall of the second growing season.  

medicinal uses

Valeran root is widely used as a mild sedative and for insomnia.  In the Naturopathic Handbook of Herbal Formulas, it is described as, “an excellent nervine for treating anxiety and tension, and a gentle, safe sleep aid.  Valerian’s antispasmodic action makes it a strong muscle relaxant used in muscle cramping, uterine cramps, and intestinal colic.”

selecting a planting site

Valerian grows in a wide range of soils but prefers a moist, rich, well-drained loam.  This species is hardy in zones three to nine, grows in full sun or partial shade, and prefers a pH range of 6-7.  The plants benefit from adding composted manure. 

planting

Valerian is easy to grow and can be cultivated by direct seeding, transplanting, or by dividing the roots.  Johnny’s Selected Seed Co., Winslow, Maine, recommends the following guidelines for starting seeds (direct seeding and in flats).  Direct seeding can be done outside in spring or fall.  In a well-prepared planting bed, sow seeds one inch apart at a depth of three-eighths to one-half inch.  Thin plants twelve to eighteen inches apart, and space rows three feet apart.  Plants will benefit from a covering of mulch.  Do not allow the seeds to dry out and keep the planting beds free from weeds.

 To start seed indoors, sow three-eighths inch deep into a prepared soil mix in flats or pots.  Moisten, and keep temperatures at 65-68⁰F until emergence occurs.  Higher temperatures can reduce germination rate.  Once the seedlings germinate, usually seven to twenty-one days, valerian can be grown at normal greenhouse temperatures.  Transplant to outdoor prepared beds in spring when plants are five to six inches tall (usually eight to twelve weeks).  Keep the plants moist.

 Root divisions can be made in early spring or fall.  At the end of the second growing season, smaller plants grow around the base of the mature plant.  These plants can be separated from the mother plant and transplanted at the recommended spacing. Since valerian self-seeds easily, seedlings can also be found around the mother plant if plants are allowed to flower.  (Typically, for root production, the flowers are cut off the plant to allow for better rhizome development.)   

insects and diseases

Diseases for valerian, listed in Index of Plant Diseases in the United States, include powdery mildew, Erysiphe cichoracearum; rusts, Puccinia commutata, P. extensicola, and P. valerianae; and leaf spots, Ramularia centranthi, R. eamesii, and R. valerianae.

harvesting, cleaning, and drying

Roots are usually dug in the fall of the second year, after the aerial parts begins to die back to the ground.  Valerian roots can also be dug in the spring, before the plant bolts and flowers.  A spading fork or other hand-digging tool can be used as well as a root digger.  Tim Blakley, Medicinal Herbs in the Garden, Field, and Marketplace, recommends cutting the above ground stalk before harvesting the root.  As the roots are pulled out of the planting beds, be careful to not damage or break them.  Shake the roots free of dirt and carefully remove only roots that are valerian.  Put plants in the shade until harvesting is complete.  When ready for processing, it is recommended to wash valerian roots with a pressure hose or a rotary root washer to remove all soil and stones that may get lodged in the crown of the plant.  It may be necessary to separate the fibrous root system and cut the rhizome to clean the roots effectively and to get uniform drying. 

 The roots need a warm location with adequate airflow for drying.  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.  Recommendation for the best drying method is to dry valerian as quickly as possible without overheating, according to Jim Douglas in his article, Valerian – Valeriana officinalis.  Dry the roots at approximately 104⁰F and provide good airflow.  Store dried roots in a cool, dry, dark location in plastic bags, light-proof sacks or drums.  Blakley estimates that valerian yields per acre can range from 1500 to 2500 pounds of dried root.   

markets  

Currently, the largest market for valerian is Europe.  According to Blakley, there is a growing market for cultivated valerian root – fresh and dried.  Most of North American Valeriana officinalis that is on the market is from cultivated sources.  Demand in strong for production of certified organic material. 

Douglas, Jim. 1993. Valerian – Valeriana officinalis L. Ruakura Agricultural Research Centre, The New Zealand Institute for Crop & Food Research Limited. Christchurch, NZ.  Click here for Web site. pp. 6.

 Felter, Harvey Wickes, and John Uri Lloyd. 1898. King’s American Dispensatory.  Henriette Kress. Click here for Web site.

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

 Foster, Steven, and James A. Duke. 1990. A Field Guide to Medicinal Plants Eastern and Central North America.  Houghton Mifflin Company, Boston Mass. 366 pp.

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

 Grieve, Mrs. M. 1995. A Modern Herbal Valerian – herb profile and information. Click here for Web site.

Herbal Research Publications, Inc. 1995. Naturopathic Handbook of Herbal Formulas: a Practical and Concise Herb User’s Guide. Herbal Research Publications, Inc. Ayer, Mass. 217 pp.

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

 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.

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.