Crossbow in the vegetable garden
I have an area that I was planning to make into a vegetable garden this spring. There were a lot of blackberries in the area and so my dad sprayed it with Crossbow mixed with some fertilizer. I wasn't planning on using any herbicides or pesticides...Looking at the label, it recommends waiting 3 weeks to re-seed but it also says not to use in any crop areas and that it can stay in the soil up to 12 months. Is it safe to grow any food crops in the sprayed area? thank you for your help
Lane County Oregon
I spoke with the experts at the National Pesticide Information Center (NPIC) about your dilemma. It looks like there are different formulations of Crossbow available. The two possible active ingredients are 2,4-D Ester and/or Triclopyr. Your label will have a box on the front page indicating the active ingredients. 2,4-D Ester has a shorter half-life (how long it takes for the pesticide to break down) and after 31 days there will be only 3% left in the soil (depending on conditions). Triclopyr, however, is much longer lasting and it can take over a year for only 3% to be left in the soil (again, this is wide ranging and depends on specific soil conditions). Triclopyr is so effective against weeds because it does stay active in the soil for longer and it is also taken up by plant roots and becomes systemic in the plant. So check the label and see what specific active ingredient was in the Crossbow that was used.
Note: The three week waiting time that is on the label is specifically for replanting pasture land for grazing which is very different than human food crops.
Since Crossbow wasn't developed for food crop applications, there isn't a lot of information available on specific replanting dates. The experts at NPIC suggested that you may be able to find more information by contacting the pesticide manufacturer directly. Crossbow is manufactured by Dow AgroScience and their pesticide hotline is 800-263-1196. They may have more information or be able to provide specifics.
Feel free to respond if you have further questions and thanks for using Ask An Expert!