08/24/2026
This is a tricky situation. Unfortunately there are no easy fixes.
Without knowing which herbicide is to blame, we can’t know for sure how long its residual effect will be on your garden. Some types of herbicide can last for years in the soil.
There are very few labs that test for the presence of herbicide in a soil or plant sample. Also, signs of herbicide contamination can mimic environmental stress or disease/pest issues. It's important to ask your county's Extension Horticulture professional for a full assessment of the situation.
If you suspect herbicide contamination or have it confirmed, you have options in how to deal with it:
> Remove all of the contaminated soil and replace it with a soil mix that you trust (the quickest fix);
> Encourage a faster breakdown of the residual herbicide by promoting soil microbial activity through frequent tilling, watering, and fertilizing (slow fix);
> Add activated charcoal or biochar to the soil to bind the herbicide (slow fix);
> If you notice that certain plant types are growing in your garden, the herbicide was selective for some plant types but not others, giving opportunity to plant a non-sensitive crop that can bioaccumulate the herbicide (slow fix).
Whichever option you choose, you need to do a bioassay pot test on your garden soil to check for continued contamination before planting again. You can do this at home.
Learn more from your county’s Extension horticulture professional; find yours at https://hles.unl.edu/
If in Adams County, call Rita Brhel at (402) 461-7209