Feverfew (Tanacetum parthenium, Chrysanthemum parthenium)

Nancy W. Callan, Mal P. Westcott, James B. Miller, and Sue Wall-MacLane Western Agricultural Research Center Montana State University

Feverfew has a long history of use as a medicinal herb. Native to southeastern Europe, feverfew is reported to be effective in relieving migraine headache. The leaf contains the active constituents and can be either used as a tea or, more commonly, as an herbal extract (Foster, 1993). Products are standardized to parthenolide, but there is a question as to whether this compound is responsible for the plant?s medicinal activity.

Feverfew is easy to grow and may be started from transplants or seeded directly in the field. The perennial plant has finely divided leaves and small white daisy-like flowers. The plant becomes woody with age and may be grown as an annual for maximum yields. The plant may be harvested before or during the bloom period, with time of harvest dependent on buyers? requirements. Several harvests per season may be possible, although late fall harvest may reduce cold hardiness. Reported yields from Australia are 2673 lb/a tea grade or 3564 lb/a manufacturing grade leaf (Rob Clark, personal communication). Foster (1993) reports that an acre should yield over a ton of dried leaf.

Western Agricultural Research Center

Feverfew seed was obtained from the USDA North Central Plant Introduction Station, Ames, Iowa and from Johnny's Selected Seeds, Albion, Maine. Feverfew PI596395, No. 161, was from Germany. Feverfew was sown in the greenhouse on March 30 and transplanted to the field on May 13. Six-row plots were 8 ft long with rows 18" apart and 10" between plants, with four replications. In 1998, plots were split and plants were harvested at either early bloom or full bloom,. After vigorous regrowth the plants that had been harvested at early bloom were cut again about 1 month later. The top 2/3 of the plant was removed and the plant material dried in a shaded greenhouse. Subsamples of dried plant material were rubbed through 1/4" hardware cloth to separate leaves and flowers from stems, and commercial grade harvest was calculated. Plant vigor was evaluated in July 1999. In 1999, the intention was to follow the 1998 harvesting plan, but insufficient regrowth was produced and only one harvest was done, at either early bloom or full/late bloom.

Table 1. Yield of feverfew at the Western Agricultural Research Center, 1998

Dry weight (lb/acre) Strain Harvest schedule First cutting Second cutting Total harvest Plant Tops Leaves/ Plant Tops Leaves/ Plant Tops Leaves/ flowers flowers flowers Johnny?s July 30 and Sept 3 1992 1245 2593 1698 4585 a 2944 a Aug 11 3085 2005 3085 b 2005 b # 161 July 27 and Sept 3 2572 1543 3232 2165 5804 a 3708 a Aug 7 3594 2327 3594 b 2327 b

Total harvest means for each harvest schedule (double vs. single cutting) followed by different letters are different by LSD (P<0.05)

Productivity was highest the first year. Harvesting twice resulted in greater total yields than a single harvest (Table 1). The German strain bloomed earliest and produced a larger first harvest, but strains did not differ in total yield. Yields declined the second year (Table 2). Winter survival was a contributing factor, as overwintering mortality was greater in the German strain after two cuttings the previous year (Table 3). In 1999, yield was different between strains only in the early-harvested plots that had been cut twice the previous year. The strain from Johnny?s, which exhibited better winter survival, was more productive than was the German strain after double harvest the previous year.

Feverfew can be grown as an annual for maximum productivity in colder climates. If perennial culture is desired, it is necessary to harvest early enough to allow sufficient time for regrowth in the fall.

Table 2. Yield of feverfew at the Western Agricultural Research Center, 1999

Dry weight (lb/acre) Strain Harvest date Plant top Leaves/flowers Johnny's July 13 3546 1756 Johnny's August 4 2919 1679 Mean 3233 a 1718 a #161 July 9 1731 843 #161 July 20 2010 1106 Mean 1871 b 975 b Means within a column followed by different letters are different by LSD (P<0.05)

Table 3. Second-year vigor of feverfew plants at the Western Agricultural Research Center, 1999

Percent of plants vigorous in 1999 Strain One harvest in 1998 Two harvests in 1998 Johnny's 100 a 97 a #161 92 a 80 b Means within a row followed by different letters are different by LSD (P<0.05)

Acknowledgments:

Seed was provided by Johnny's Selected Seeds, 1 Foss Hill Road, RR1 Box 2580, Albion, ME 04910-9731

References:

Foster, S. 1993. Herbal Renaissance. Gibbs Smith, Layton UT.

Hornok, L. 1992. Cultivation and Processing of Medicinal Plants. John Wiley and Sons, Chichester, UK.