|Sunflowers stunted by herbicide contamination.|
We're posting this to our site in the hopes that people reading our posts about the deep mulch method of gardening and folks using grass clippings, animal manures, or hay or straw for mulch, or to build their compost piles will use discretion in acquiring those materials. Some herbicide chemicals can remain toxic for several years in plant materials and manure.
|Herbicide-contaminated tomato plants|
It is ironic that, after championing the use of "local", organic materials to create garden fertility (instead of imported, concentrated fertilizers that are often mined and produced unsustainably) that we experienced such devastating results.
Of the hundreds of tomato and pepper seeds we started this year, not a single one was unaffected and all had to be thrown out!
If you are still using chemicals to fight weeds, we urge you to stop. Herbicide contamination is another reason to only eat organic foods as they minimize the use of these chemicals in our environment.
Here are links to two excellent articles we found on the topic:
(LINK) - Gardener Alert! Beware of Herbicide- Contaminated Compost and Manure
(LINK) - Herbicide Carryover in Hay, Manure, Compost, and Grass Clippings
We encourage you to do research of your own and share your comments below if you have relevant experiences.Here are the details of our situation:
Right from the start, some of our seedlings did great but other varieties would do fine until they began putting on their second set of leaves and the leaves would begin curling in a distorted manner, never fully unfurling so the plants couldn't photosynthesize (get energy from the sun). We also noticed that some of the plants formed gold-colored nodules right below the soil-level where the roots begin to branch and on their root tips.
|Onion starts did fine!|
- cabbages and kales
- cucumbers, squash and melons
- peas, beans
- sunflowers, zinnias, marigolds
|Starting seedlings - before we knew our soil was contaminated.|
|OSU students sifting compost and manure to make potting soil.|
- 2-parts of our compost
- 1-part of composted horse manure/sawdust and
- a small amount of coffee grounds.
The reason we think it was our potting soil that was contaminated is that none of our seeds planted directly in the ground showed any of these same signs of distress.
|Compost bins(left) and grass-piles (center) for garden fertility.|
- Do not use contaminated compost or manures to make "compost tea" if you are going to be pouring it on any of the families of plants listed above. In addition, potatoes (in the same family of plants as tomatoes, peppers, eggplant and tomatillos - solanacea should not be grown in contaminated soil or had tea applications. Lettuce may also be susceptible).
- Some chemicals can remain active in the soil. compost or manure for two years or more.
- They can harm vegetable and flower plants in concentrations as low as 3 parts-per-million!
- While it is unlikely that enough of these chemicals would be present in lawn clippings from a residential source to contaminate your compost or mulch-pile, there are several herbicides available from garden-stores that do contain aminopyralid or clopyralid.
-- Here is an alphabetical list of herbicidal active ingredients, with trade names following.
We encourage you to do research of your own and share your comments below if you have relevant experiences.
|Carrots (front) and nasturtiums (back) are thriving this year!|
|Steve Rose, in a previous year, with tomato plants he donated to the Sharing Gardens and Monroe's Food Pantry.|
|Thank goodness for kale! Delicious, nutritious and unaffected by herbicide contamination.|