Killer Compost and Other Creeping Concerns

August 12, 2011

Have you noted any public assurances of safety that later turned into cautions and warnings regarding the latest and greatest new chemical or genetic discovery for the garden? Consider concerns over the impact of Imidacloprid on honeybees and questions regarding the quality of the research that was used to support its approval.

Who know’s where the recent USDA approval of engineered alfalfa will lead us, or whether the deregulation of Roundup Ready Kentucky Bluegrass will create an even bigger problem of herbicide resistant super-weeds! There have been previous reports of deadly killer compost contaminated with Clopyralid, and now questions are being raised regarding another “approved” product that is now being linked to some unadvertised consequences.

I think there’s good reason to be concerned and cautious about the products that we use both on the farm and in the backyard, regardless of what the regulators or manufacturers have to say about the safety of their application. Even the organic gardener needs to be aware and alert to the risks imposed by things like killer compost and outside chemical use that poses a risk to honeybees and other pollinating insects.

Following is an Imprelis warning that I received recently from Mother Earth News:

We at Mother Earth News want to let you and Veggie Gardening Tips readers know about yet another dangerous discovery for gardens and lawns: Imprelis herbicide in treated grass clippings. This new herbicide from DuPont is designed for use on cool-season grass, but its effects have been seen in the garden and on trees throughout the Midwest and Mid-Atlantic states – including Pennsylvania.

Here’s what we know:

  • DuPont warns that grass clippings from lawns treated with Imprelis should not be used for mulch or composting.
  • Conifer trees near lawns treated with Imprelis, especially Norway spruce and white pines, have shown signs of damage after Imprelis was used. Signs include brown and curled growth.
  • Damage has been reported in Pennsylvania, Minnesota, Iowa, Kansas, Indiana, Nebraska, Wisconsin and Delaware.
  • Applicators are supposed to inform residents and property owners of the dangers this herbicide poses and warn them not to use clippings for mulch or compost.
  • DuPont recently sent a letter asking applicators to spray well away from the root zone of trees and shrubs and to make sure no drift or runoff could impact those ornamentals.

If you suspect that your trees or garden plants have damage from Imprelis, please get them tested through your local Extension service. They may also have tips to minimize damage.

Mother Earth News is interested in hearing about any experiences that you may have had with killer compost or damages related to applications of Imprelis in or around your garden or yard.

Add this to the reasons why I like the idea of municipal yard waste collection and composting facilities, but will never spread any untested mulch or compost produced there onto my vegetable garden! Likewise for collecting grass clippings from lawns that may have been treated with non-organic and potentially toxic fertilizers or herbicides.

Other Related Vegetable Gardening Posts:

  • Great post. I compost at home and try to be careful about what I add. We are not in a neighborhood so we don’t have to worry about neighbors using spray, but I do have to watch out for my father-in-law… he would use fertilizers and weed killers everywhere in my yard if he had his way!

  • Kenny Point

    Thanks Shannon, I know what you’re up against… my dad would cut down all the trees in my yard if he had his way!

  • Barb Keeler

    Thanks for the important information, Kenny. I had not thought about it before composting grass clippings from the new neighbor. It’s another thing to be aware of.

  • Scott

    Yes thanks again will pass this information along!


  • intie

    Gardening really starts in the soil. Thinking about what goes on a microscopic, bacterial level is something most of us rarely think about, but proves time and time again to really affect the quality and abundance that our garden yields. Investing in soil inoculants means investing in the health and fertility of your soil for years to come. I think more people should be aware and this site,, is a great resource to get all garden enthusiasts on a path toward a better and healthier harvest!

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