Poison in the Compost

No, not that Poison

I’ve blogged about the dangers of  herbicides in compost before, but it’s worth repeating. Mother Earth News has been doing some excellent reporting on two herbicides, clopyralid and aminopyralid, that can decimate your garden for years should your compost get contaminated by them. I received the following note from Mother Earth news:

“As the garden season ramps up, we at Mother Earth News want to let you and Homegrown Evolution readers know that you may want to screen any hay, grass clippings or compost you bring into your gardens, to assure the materials are not contaminated with persistent herbicide residues (most often clopyralid and aminopyralid). As our reports included below indicate, these chemical residues can kill plants or severely stunt their production, costing gardeners money and time.

What do you need to know about contaminated compost?

  • Affected plants show signs of curled, cupped leaves, wilting new growth and poor germination in tomatoes, peas, beans, lettuce and other garden crops.
  • The chemical residues causing the problem can be present in grass clippings, in manure of livestock that has eaten sprayed plant matter or in compost made from contaminated materials. These herbicides do not biodegrade during composting and can persist in your soil for several years.
  • Contaminated materials have been found in municipal, organic and conventional bagged compost.
  • To prevent contamination, ask questions before buying manure or compost that contains manure. If the seller doesn’t know if it’s safe, don’t buy it, or use this cheap and easy home test to be sure it’s safe.
  • Anyone who suspects they have detected contaminated material should notify their local Extension agent and news media, as well as Richard Keigwin at the EPA and the product manufacturer (if purchased).”

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[email protected]> I’ve done the home test linked to above and so far I’ve not found any problems. My friend Tara Kolla of Silver Lake Farms has done the same and also found no herbicide residues. That being said, it pays to be careful. And let Mr. Keigwin at the EPA know that, as organic gardeners, we’d all apprciate that these poisons not be used in the first place.

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3 Comments

  1. I usually use cucumber seeds to do these kind of tests. They come up fast, are sensitive to herbicides and have big leaves. Plus you get more in a package than peas or beans. Do you know if peas and beans are extra sensitive to these toxins?

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