St. John’s Wort Depresses California Ranchers

The same St. John’s Wort which so many Americans are now buying to control mild depression has distressed California ranchers for decades. Known to them as Klamath weed, the plant, brought to the United States by Europeans perhaps as early as the 1600s, grows prolifically and is harmful to livestock. “Animals don’t like to eat it, but if they do, they become photo sensitive,” said UC Integrated Pest Management weed ecologist Tim Prather. “The animals will get dermatitis and lose hair.” The introduction of Chysolina beetles has helped control the weed, but UC Cooperative Extension livestock advisor for Fresno and Madera counties Neil McDougald says several hundred acres in Madera County are virtually unusable because of Klamath weed infestation. Conversely, there’s growing interest in cultivating St. John’s Wort. UCCE farm advisor in Tuolumne County Franz Rulofson reports a local farmer has planted five acres to the crop. For more information, contact Tim Prather at (559) 646-6534, prather [at] uckac [dot] edu; Neil McDougald at (559) 675-7879 x 207, nmcdougald [at] ucdavis [dot] edu and Franz Rulofson at (209) 533-5695, fcrulofson [at] ucdavis [dot] edu.