Question of the Week
Answer: There are several alternative herbicides available from Peaceful Valley Farm and Garden Supply and other companies that have OMRI listing.
Below is a list of some articles and other sources dealing with the use of vinegar as a natural herbicide. Some practices mentioned in these resources may not be allowed by your certifying agency. As far as I can determine, OMRI allows herbicides using acetic acid as an active ingredient if they are natural source only, and are registered with EPA. If the natural acetic acid is not listed as the active ingredient (non-active ingredient or inert), then the product 1) must have natural acetic acid content of less than 8% before it is added to the formulation, 2) must have natural acetic acid contents less than 5% as a final product, and 3) must have another ingredient listed as the active ingredient.
Remember, organic production practices and materials needs to be approved by your USDA approved, certifying agency and written into your organic system plan. Each certifying agency has different interpretations on approved control methods and materials. You should also check with your certifier with any questions.
Please consider the following advice with respect to use of material inputs:
a. List every material you use or plan to use in your Organic System Plan (OSP) that you submit to your certifier as required.
b. Identify the source and/or manufacturer of every material.
c. Attach a label with a list of all ingredients including inerts.
d. If the manufacturer does not provide a complete list of ingredients for the product, check to see if it is on an approved list of Brand Name materials, such as OMRI or WSDA (see www.OMRI.org and http://agr.wa.gov/foodanimal/organic/materialslists.html)
Note: if someone says their product is OMRI listed or cites an article that states that they are, or even shows the OMRI seal on the packaging, beware. It is the producer’s responsibility to verify the truth of that statement by checking the current lists on the website. Inclusion on the list must be renewed every year. Products may be listed one year and not the next. Reformulations (common in the industry) may render a product non-compliant or possible make it compliant. In some cases, producers will be required to document which lot number of a product they used in order to verify compliance.
e. Be sure everything is in your OSP and that it is approved by your Certifier before you use it. Your certification depends on it!
f. Keep documentation of every input material purchase and application for 5 years.
Anon. 2003. Vinegar-based and citrus-based weed killers. Fine Gardening. May-June. p. 88, 90.
Chinery, David. 2002. Using acetic acid (vinegar) as a broad-spectrum herbicide. Rensselaer Horticulture. 5 p.
Jensen, Erika. 2004. Organic inputs: distinguishing myths from realities. Organic Broadcaster. No date. p. 6.
Peaceful Valley. 2006. AllDown Green Chemistry Herbicide, Matran EC, Pest Solution Chart, and Using our products & organic certification. 7 p. www.groworganic.com
Shaffer, Bob. 2003. Vinegar coffee, grapes and ginger. 4 p.
Williams, Greg and Pat. 2003. Commercial acid-based herbicide. HortIdeas. March. p. 1.
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