Q. When am i able to mow a freshly seeded lawn? Prevent mowing right until the grass seedlings reach a minimum of 3½ inches high. The longer you can hold out, the greater. Really should I Aerate and Dethatch simultaneously? Of course, you are able to aerate and dethatch simultaneously. https://www.no-bs-yardwork.com/blog/best-winnipeg-grass-cutting-seeding-services