Overseeding is planting new grass seed into an existing lawn, usually to improve its density. Here I'm overseeding the area I renovated from scratch this past Fall. It was a successful renovation, but I had a few low spots and some areas that didn't germinate as successfully, so this Spring overseed will help it thicken up to my standards more quickly. A core aeration just before seeding helps, but I'm largely foregoing that on my lawn to avoid unearthing weed/poa seeds. Note: THREE @land.zie la