They may not be visible on the soil surface, but dozens of white grubs could be burrowing in your garden soil. These insects feed on your vegetable plants' roots, according to Oklahoma State University, and may cause widespread wilting and death. Several physical and chemical controls can help deter grub infestations and kill any grubs that are already present in your soil.
Remove all lawn grass and grassy weeds from in and around your vegetable. Grassy patches attract the adult beetles that lay the eggs which later turn into grubs.
Till the garden soil every spring and fall. Use a spade for small garden areas or a mechanical tiller if you're managing a large garden plot. This exposes the hidden grubs and helps dry them out and kill them, according to the University of Wisconsin.
Mix a diazinon-, chlorpyriphos- or permethrin-based granular pesticide into the soil before planting your vegetables, according to Oklahoma State University. Apply the pesticide as directed by its labeled guidelines, as toxicity varies widely by product.