Valerian

The dried roots and rhizomes of Valeriana officinalis L. yield the drug valerian, which has traditionally been used as a sleep aid. The plant is native to moist woodlands of Europe and western Asia, but has become naturalized in the United States. The fibrous, often unbranched roots may be harvested the first or second year after seeding. The roots have a strong odor when dry. A stalk of white to pink blossoms is usually produced the second year. Flower removal is often practiced to prevent weedy seedling establishment.

Age at harvest

Valerian was established from transplants on May 13, 1998 at the Western Agricultural Research Center. Plants were 1 ft apart in the row and rows 1.5 ft apart, with four replications of six-row plots. Roots from the first planting were harvested after two years on October 11, 1999, but yield was reduced by a root-rotting fungus, identified as Phoma sp. (Table 1).

A second planting was established May 22, 2000 and one-year-old were harvested on October 23, 2000. Production from first-season plants was satisfactory, at about 0.11 lb/plant, and there was no evidence of disease. All subsequent studies were conducted with a one-year harvest.

Cultivar and plant density studies

'Artener Zuchtung' (also known as Anthos) and common valerian (Johnny’s Selected Seeds) were planted at 18” x 8” spacing in four replications of 12 plants per plot. Common valerian was also planted at 8” x 16” spacing. A randomized complete block pattern was used Transplants were planted in the field on May 31, 2001. Plants were harvested on October 16, 2001. The study was repeated in 2002, with transplants planted in the field May 16, 2002 and harvested on October 7, 2002. After harvest the roots were washed and dried at 90F. Analysis of acetoxyvalerenic acid, valerenic acid, valerenal, and total valerenic acids in the roots was performed by Dr. Titut Yokelson of Nutritional Laboratories Inc., Missoula, MT.

18 x 16 inch spacing.
P values for year: 0.0271; cultivar: ns, year*spacing ns

P values for year: 0.0034; cultivar: <0.0001; year*cultivar 0.0009

There was no difference in root weight or yield between the two cultivars, although root weight and yield were higher in 2002 than in 2001, possibly due to an earlier planting date (Table 3). Composition of the roots of plants at low and high densities was similar with the exception of acetoxyvalerenic acid, which was higher in plants growing at low density (Table 4). Roots of plants at the closer spacing weighed less than those planted farther apart, but total yield was significantly greater with higher plant density. However, growers must keep in mind that costs for transplants, planting, harvesting, and processing increase as the number of individual plants is doubled. Growing valerian as an annual may be the best practice where disease is present.

Cultivar = ns