Scotts GrubEx should be applied in Spring and Early Summer prior to grub egg hatch for best results and will remain in the soil for up to 4 months. Adequate watering with 1 inch of water/rainfall is required following the application is required and should show results in 1-2 weeks.
Per the product label, this is applied 2.87lbs per 1000 sq ft and can be done once a year.
Scott's GrubEx is not labeled to be used in areas with ediblies. We would recommend reaching out to the manufacturer directly to confirm when it is safe to plant vegetables in the area, they can be reached at 866-476-9244.