Vinegar Types, Methods of Making Vinegar
Spray Weeds With Vinegar?
By Don Comis
May 15, 2002
Some home gardeners already use vinegar as a herbicide, and some garden
stores sell vinegar pesticides. But no one has tested it scientifically
Agricultural Research Service scientists offer the first scientific
evidence that it may be a potent weedkiller that is inexpensive and
environmentally safe--perfect for organic farmers.
ARS researchers Jay Radhakrishnan, John R. Teasdale and Ben Coffman in
Beltsville, Md., tested vinegar on major weeds--common lambís-quarters,
giant foxtail, velvetleaf, smooth pigweed and Canada thistle--in
greenhouse and field studies.
They hand-sprayed the weeds with various solutions of vinegar,
uniformly coating the leaves. The researchers found that 5- and 10-percent
concentrations killed the weeds during their first two weeks of life.
Older plants required higher concentrations of vinegar to kill them. At
the higher concentrations, vinegar had an 85- to 100-percent kill rate at
all growth stages. A bottle of household vinegar is about a 5-percent
Canada thistle, one of the most tenacious weeds in the world, proved
the most susceptible; the 5-percent concentration had a 100-percent kill
rate of the perennialís top growth. The 20-percent concentration can do
this in about 2 hours.
Spot spraying of cornfields with 20 percent vinegar killed 80 to 100
percent of weeds without harming the corn, but the scientists stress the
need for more research. If the vinegar were sprayed over an entire field,
it would cost about $65 per acre. If applied to local weed infestations
only, such as may occur in the crop row after cultivation, it may only
cost about $20 to $30.
The researchers use only vinegar made from fruits or grains, to conform
to organic farming standards.
ARS is the U.S. Department of Agricultureís chief scientific research