Are Dormant Sprays Organic?
I have left this article here for historic purposes. Neither copper sulfate nor lime sulfur is available any more for homeowners. Liquid copper is available and is not organic. Copper soap sprays are available and at least one is OMRI certified.
We are often asked if the conventional dormant spray materials
are considered organic. What people mean by organic varies, but certified
organic farmers have very specific regulations they must adhere to. These can
be found in the CCOF guidelines, which is available in its entirety at the CCOF
website. The materials in question are copper sulfate, lime sulfur, and dormant
All three common dormant spray materials may be accepted in the California Certified Organic Farming certification standards*.
They are "regulated" materials which "may be used only if no alternatives are
feasible." This means that CCOF inspectors will look at what other actions the
grower is taking to mitigate the need for the chemical (pruning, cleanup,
etc.). An inspector told me the general principle is that the material must not
have been chemically altered in a significant way in production, so copper
sulfate is acceptable while copper hydroxide (Kocide) is not (in spite of the
note below); sulfur dust is acceptable and widely used, but lime sulfur is
Both copper and sulfur are widely used in organic farming for disease prevention. The "narrow-range" petroleum oil sprays referred to are the so-called "superfine" oils such as Safe-T-Side or SunSpray oils. The older dormant oils such as Volck oil may not be acceptable.
The following are taken directly from the CCOF Handbook:
"Includes Calcium Polysulphide. Foliar application as a fungicide allowed.
May be used as an insecticide only if there are no feasible alternatives."
"These include copper compounds that are exempt from
tolerance by the EPA: Bordeaux mixes, copper hydroxide, copper sulfates, copper-zinc chromate, copper oxychloride, and copper oxides. These may be used as algicides, bactericides, fungicides, molluscicides, for arthropod control, wood treatment or as micronutrients. Cannot be used as an herbicide. Shall be used in a manner that prevents excessive copper accumulation in the soil. Build-up of copper in soil may prohibit future use. Use with caution. No visible residue is allowed on harvested crops. Copper-chromium arsenate is prohibited -- see 'Arsenate treated lumber'. (See 'Micronutrients'.)"
"Regulated to narrow-range (415 to 440) petroleum derivatives. Allowed for use in organic production as suffocating or stylet oils on foliage, as dormant or summer oils, and as inert ingredients. Direct application to harvested crop is prohibited. Petroleum distillates may not be used as weed or carrot oils in organic production. Land covered with petroleum derived pavement or road oils cannot be certified for three years following application. (See inerts statement at the end of SS8.2.1.)"
* for more information, go to the CCOF website at www.ccof.org/ and look at to their Certification Standards.
© 2008 Don Shor, Redwood Barn Nursery, Inc., 1607 Fifth Street, Davis, Ca 95616
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