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Questions? Write me at fullcirclegardener @ cableone . net.

Sick Tomatoes: Lesson Learned

Devastated Red Oxheart Tomato
On Monday I posted that I have some very sick tomatoes and I was in contact with some plant experts to try and figure out what is wrong with them.

I first contacted the National Gardening Association with pictures and questions.  They suggested the possibility of Tobacco Mosaic Virus but also recommended that I contact my local county extension.  I took their advice and emailed my pictures and questions to my local extension agent.  He thought that it looked like herbicide damage, but forwarded my email to the NDSU Plant Pathology Diagnostics Lab.  I spent 2 days in communication with the Plant Lab and ended up taking some of my plants to the Lab at NDSU.  They confirmed that my tomatoes are displaying classic signs of herbicide damage.

The question then turned to where in the world would that herbicide have come from.  The first suggestion was my mulch.  I was able to rule that out because I had observed the disfiguration of the tomato leaves before I put down the mulch a couple of weeks ago (besides the fact that I am very careful to keep treated grass clippings out of my garden!).

The focus then turned to the composted manure that I had used to amend my garden this spring.  I have gotten manure from the same source in the past and had asked myself the same garden safe compost questions that I would for any compost I had not made myself, but I contacted my source again and verified that they had not knowingly fed the animals herbicide treated food.

This left me stumped until I realized that certified weed-free hay is often required for traveling competitive animals, which some of these horses are.  It is very likely that they had eaten treated hay on occasion at the very least.  According to the Plant Lab, water soluble herbicides will pass through animals and remain potent for years after. So now I have an answer.  Most likely, my garden is contaminated by a water soluble herbicide that was introduced via manure I had used to amend the soil this spring.  :'(

Unfortunately, they were unable to tell me how long the herbicide will affect my garden, or if/when any produce from the garden will be table safe.  One individual from the lab had experienced similar damage in his garden last year and said that the plants did not exhibit negative effects this year, and that his family ate out of the garden even though it had been contaminated.  I will have to make that decision for my family sooner or later, but for now I have pulled up the four worst affected tomatoes only.  I am going to leave and observe the rest my plants until my husband & I have decided what to do.

This has been a not so pleasant garden adventure but a valuable lesson learned.  I do want to take this time to say we have great resources available to us, no matter where we live, through the National Gardening Association and local county extension!  Do not be afraid to contact either of them if you have questions or concerns.  They will at least be able to direct you to someone who can help you.

Happy Gardening! :}


  1. Thanks for this, had never thought of water soluble herbicides being an issue. Will look more closely at this as a possible issue as I used a lot of hay as mulch this year and lots failed

  2. Tilli - I hope the hay is not your problem, & that you find your answers. (Don't forget to take into account any unusual summer weather - we've certainly had some in my area & gardens are showing it!)

    It is so frustrating to think you are doing the right thing and think you have all your bases covered and then find you made a mistake! I am thankful to be getting some produce, even if it is a far smaller amount than I had hoped for, this year. :-/


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