The New Wave of
Natural Herbs -
Medicine or Menace?
By John Brinkley
Scripps Howard News Service.
c. 1998
WASHINGTON -- St. John's wort and other medicinal herbs may be great for what ails you, but they can be hell on the environment.
The growing popularity of these plants, many of which are not native to the areas they grow in -- or even to the United States -- has led to their spread across the countryside, where they have crowded out native plant species and driven some toward extinction.
St. John's wort and other herbal plants can spread from the farms where they're cultivated, if growers aren't careful about when and how they harvest them.
"If people want to start planting hundreds of acres of klamath weed, and do not keep the plant from staying in the growing areas and let it go to seed, the plant will just spread from its growing area," said Nate Dechoretz of the California Department of Food and Agriculture.
"For many years, St. John's wort was a major pest to agriculture in California," he said. "Bio-control agents have been developed and released and established that resulted in pretty darn good control."
Now heavily marketed as a natural anti-depressant, St. John's wort is in some places considered a noxious weed.
In Ventura County, Calif., for example, St. John's wort -- also known as hypericum and klamath weed -- grows wild throughout the county, choking out native plant species. State, county and federal agriculture departments have introduced beetles and moths into the ecosystem to reduce the prevalence of the weed.
When Rick White of the U.S. Agriculture Department's Natural Resource Conservation Service found out St. John's wort was being marketed as an herbal medicine, "it sort of surprised me," he said, "because St. John's wort in general is considered a poisonous plant to livestock. It was introduced into the United States (from Europe), particularly the northwest portion of the country, and became quite a problem, invading plant communities and so forth."
St. John's wort grows wild throughout much of the United States and Canada.
In California, when a farmer wants to plant it, the state Food and Agriculture Department refers the request to the agriculture commissioner in the farmer's home county.
"This is a matter of concern to many counties and many will decline the request," Dechoretz said.
Other popular herbs that various state agriculture departments list as noxious weeds include:
-- Milk thistle, used for liver disorders.
-- Common burdock, advertised as a blood purifier, a treatment for skin diseases and a weight-loss supplement. In addition to choking out native plant species, burdock "is a very serious threat to sheep as the burs can significantly damage the quality of the wool," the Colorado Weed Management Association reports.
--Wild fennel, used to relieve gas and acid stomach, is on California's list of "most invasive wildland pests."
-- Yellow toadflax, introduced from Europe, is now "a serious problem to rangeland and mountain meadows," according to the Colorado Weed Management Association.
-- Foxglove, a source of the heart stimulant digitalis, is an "escapee from cultivation" that grows in "disturbed" areas, such as clear-cuts, said William Gregg, invasive-species coordinator for the U.S. Geological Survey.
"It's an extremely attractive plant and, unfortunately, some of our worst invaders were brought over here because they had horticultural properties that people really liked," he said.
Invasive herbs needn't be a problem as long as herb growers harvest their plants before they go to seed, Tim Blakley of the National Center for the Preservation of Medicinal Herbs told National Food Merchandiser, a trade magazine.
"Quality growers harvest before the plant goes to seed anyway," he said.

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