Seeded lawns require the longest time period between planting your grass and mowing. Because you must wait for seeds to germinate, you cannot cut the grass until two months have passed. If you planted your seeds during their active growing season, the blades should reach a 3 to 3.5 inch height after eight weeks.Click to see full answer. Keeping this in view, is it OK to mow after overseeding?Thus, it’s important to identify the type of grass used for overseeding. Once these height ranges are achieved, you can start cutting the grass for the first time. In general, however, you should not do any mowing during the first two weeks to four weeks after planting the new grass seeds.Subsequently, question is, can you put cut grass over grass seed? Grass clipping are fine too as long as they are not wet clumps sitting on the lawn after a rain, becuz they can suffocate the lawn quickly Mulch mowing or side shooting accomplishes a nice covering for overseeded lawns Furthermore, should you mow your lawn before seeding? Mow the lawn short, 1-1/2 inches before overseeding to keep grass and weeds from competing with new seedlings. Short mowing helps prevent the seed from lodging in tall grass and lets light reach the new seedlings. Use a grass catcher on the mower or sweep up excess clippings.Can you just sprinkle grass seed on lawn?By applying grass seed over an existing lawn, you can help fill in bare spots and reinvigorate your lawn. The weather, kids, and pets can be tough on lawns. Lack of water, too much heat, wear & tear, and other problems can make it look worn and thin. You can help reinvigorate your lawn by overseeding.