How to Sow Grass Seed After Applying Weed Control

Read the package on your weedkiller to see if you need to wait before over-seeding. Pre-emergent herbicides do not affect most grasses, and seeds can sometimes be sown a little more quickly after the herbicide is applied. In many instances, however, weedkillers need multiple applications, so waiting a few weeks is not a bad idea anyway. There is no need to over-seed if you add more weedkiller, then rake up the dead vegetation. Non-pre-emergents might require as many as six weeks before over-seeding.

Rake up dead weeds as well as any dead grass or roots.

Look on the grass seed bag to determine the required quantity of seed for over-seeding based on the size of your yard. If you are unsure of the size, measure the length and width, then multiply the numbers together to get square feet. If the package specifies amounts in yards, divide the number by three to get yards.

Fill the spreader with no more than half the required seeds. Walk over the lawn pushing the spreader in front of you. Walk in rows back and forth. Once done, fill the spreader with the rest of the seed and walk in rows perpendicular to the previous direction.

Sprinkle topsoil over the seeds with your hands. Seeds grow best if covered with a quarter inch of soil.

Water the yard daily until grass starts to grow. Once you see growth, reduce watering to twice a week with no more than 1 to 2 inches of water per week.