Pesticides and/or Herbicides Residual Herbicides

Residual Herbicides in Composts – Part I

Our area is rural and as I have mentioned before, anyone using organic practices here is in a small minority.  Farmers spray the surrounding fields with herbicides and results can be seen by almost anyone paying attention.  A friend who lives within a few miles of us said, “Around the edges of the field where the spray isn’t concentrated enough to kill the weeds it causes the normally straight stems to grow in a corkscrew spiral.”

Even more alarmingly, he had seen this same symptom on a tomato that he had grown with purchased potting soil and/or compost. And then, to top it off, he saw a program reporting on the growing problem of residual herbicides in compost. Upsetting to say the least.

More About the Problem

From what I could find on the internet this problem came to light about the year 2000. Washington State University composting facility and the Spokane Regional Compost Facility found traces of persistent herbicides in their composts.

Their compost had damaged plants at local gardens and nurseries.  Also, incidents in other Washington counties, Pennsylvania and New Zealand came to light.

There seemed to be two culprits, clopyralid and picloram, both active ingredients in herbicide products.

Products containing clopyralid are used especially on lawns to control clover, dandelions, and other broadleaf plants. It is also used on asparagus, strawberries, blueberries, Christmas trees, sugar beets, grass hay, straw and cereals.

Those containing the picloram are mainly used to control weeds in pastures, rangelands, on railroads and near power lines.

This is what happens:Pastures lands are sprayed.  In many cases the hay is harvested and fed to cattle.  If their manure and bedding is  taken to a compost facility the herbicides are still intact. The same applies for grass clippings and yard trimmings that have been sprayed with herbicides and are also components of compost.

And the finished compost can still contain some of the herbicide that can be harmful to plants like legumes, sunflower, potatoes, and tomatoes at the level of 10 parts per billion or lower.

In the case of clopyralid, supposedly humans and wildlife have a relatively high tolerance. Thus, anything below 50 parts per billion was not measured in most testing prior to these incidents in Washington State.

If you want to read more here’s the link:

Problem Commentary

Everything has its price and doing away with weeds in the fields and lawns using chemicals have had more far reaching effects than anticipated.

This problem of residual herbicides being found in compost may seem small to some and big to others. (It will seem especially insignificant if you know little about what is really going on.) If this were the only problem out there along these lines, one could be encouraged by the possibility of finding a way to deal with it and correct it. Unfortunately, it seems we live in a world of “must have the quick fix for everything” and to heck with the price to be paid and what’s best in the long run. Thus, the chemical problem and how it has effected our environment and sadly, our food supply is staggering.

If you’re not outraged – at least a little – then you must not be paying attention. And that can happen.

Sometimes there is so much to deal with that I think people get caught up with the problems and difficulties of the day.  Not to mention, they feel helpless to do anything about what’s going on with big companies or the government. They are already overwhelmed and don’t know what to do, so they do nothing — don’t even try.

Many follow the masses and give in to peer pressure so they won’t have to deal with the stress of being looked at as “odd”.  It’s just not in them to buck the crowd —- even if it’s the right way.

I feel badly for farmers who are so steeped in the chemical way – the way of their peers – that they have long since passed the point of considering a more sustainable way of farming again. They are convinced it is not possible.

I have read about some conventional farmers who have made the change to organic practices.  In almost every case it was because they had something traumatic happen in their lives that they could directly attribute to chemicals or unnatural practices. Suddenly they saw the benefit of sustainable agriculture and/or good animal husbandry and made the change.

When I mention good animal husbandry — I am assuming that you know of horrible practices that are commonplace today, like keeping animals from light and fresh air, feeding cattle parts of other cattle, keeping animals confined in their own filth indefinitely, etc.

Good News

The good news is that even though the effects of the chemical explosion are cumulative, so are the actions we take in our lives if we take them consistently. There are some folks out there who are trying to provide us – as organic gardeners – products that will get the job done for us. By finding them and going forward in practices of sustainable agriculture we set an example that may be greatly needed in years to come.

My friend was ready to throw in the towel and not buy anymore potting soil, compost or mulch. (He is probably including grow mix with potting soil.)

In my next post I will tell you which brands of the products I think are safe and why.  I will also suggest where to buy them and where not to buy them and why.  Stay tuned in.

I think together we can make a difference.


  • We have horses and we buy hay and compost the manure with the uneaten hay for our garden. This year for the first time my tomatoes started looking very strange (gnarled new growth), also my peppers. I am outraged that now I can not use our own rich compost on our garden anymore. This needs to be made much more public. thanks

  • I appreciate your comment very much Beppy. Comments like yours may help people to become more aware of what is happening.

    Thank you for taking time to respond.

    Best regards,

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