Can cornmeal be used as a herbicide in early spring as a pre-treat for a vegetable garden? How long does it "linger"? And will it inhibit my vegetables when planting season arrives?
Herbicide in Vegetable Gardens
Certified GKH Gardening Expert
Cornmeal gluten, aka corn gluten meal, can be used to inhibit seed germination, but it won't kill growing plants. So, one way to use it would be to plant your garden and allow your seeds to germinate, then apply corn gluten meal to prevent any further weed seeds from germinating. Regular cornmeal has a different composition and won't work. This article provides the details:
As this article explains, some garden seeds will be more damaged than others:
Also, excessive moisture seems to reduce its effectiveness, so if you can rely on a couple good rains before you plant your garden, it probably wouldn't inhibit your garden seeds very much.