Canada thistle herbicide

Question

Will a Canada thistle herbicide be taken up by food/root vegetable plants (and thus be eaten)? My new home was heavily sprayed last fall professionally for Canadian thistle. The first sweet potato plants I put in this year died but their replacements look fine. I also planted squash, asparagus, raspberry and rhubarb. I’m concerned about residue in my crop.

Answer 1

There is much debate on how long herbicide residue lasts in our ground.

Here is a link that has a great overview.
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/how-long-does-weed-killer-last-in-the-soil.htm