Hi Kim,

I probably would not use that garden bed for edibles. I suggest you contact the company and ask them . There are many factors such as ; how much did you use, when did you apply it, what are you trying to grow...

https://www.preen.com/products/preen-extended-control-weed-preventer/#:~:text=Not%20for%20Use%20With&text=It%20also%20is%20not%20for,(see%20list%20on%20label).

https://cals.cornell.edu/weed-science/herbicides/herbicide-reference/treflan-trifluralin

The active ingredient is not listed as extremely toxic but if it was me I wouldn't be harvesting anything from it. 

Hand pulling is always safe and can be meditative !

Sally Granath

St. Louis County MG