Organic vegetable garden

Asked May 31, 2018, 1:40 PM EDT

Good afternoon. For several years, we have had an organic vegetable garden with tomatoes, string beans and cucumbers primarily. We also have a compost bin that we fill with last year's leaves an kitchen scraps. For lawn care, there are 2 relevant pieces of information. We always had used a mulching mower to recycle the clippings, and every year, we put down non-organic lawn treatments, primarily crabgrass pre-emergents. We also have on our property a Southern Magnolia and a Saucer Magnolia. In the past, we would rake or blow the leaves before mowing. Last year, in an effort to save time, we decided to mow over the leaves, using the lawn mower, with the bag attachment. Without thinking things through, I would occasionally put the grass clippings into the compost bin. Last year, we did not have a garden, so it was not an issue. This year, we want to have a garden, but we are concerned with the chemicals from the lawn treatments that may still may have been on the grass clippings, and now they are in the garden plot. Generally, we do eat non-organic produce. My wife is more concerned with the specific chemicals in the weed and feed crabgrass pre-emergent. Should we not use the plot this year? If no, how many years should we wait? Or is there something we can do to cleanse it? We bought sunflower seeds, but have not planted them yet. Thank You

Baltimore Maryland pesticides vegetables compost

1 Response

Many herbicides break down within a few weeks or months, so you do not have to worry about any of the grass clippings that were added to your compost last year. If, however, you used herbicides this year, we would advise you to keep the affected grass clippings in a separate area out of your compost for several months before composting them.
For any questions concerning pesticides, the National Pesticide Information Center is an excellent resource. It is based out of Oregon State Univesity and offers a toll-free hotline. If you have questions concerning any specific active ingredient in a pesticide and its persistence in the environment, you can contact this hotline to get information.