This depends on soil, traffic and humidity, but every two years is a good rule of thumb. Aeration can also pave the way to significantly increase the thickness of the grass by creating the perfect canvas for overplanting. A healthy lawn is lush and green and has no unsightly dead or bare spots. Replanting, also known as overseeding, involves sowing seeds on existing grass to prevent thinning and bare areas.
However, this doesn't have to be done every year. How often you should re-plant your lawn depends on several factors, including the amount of traffic it receives and its overall condition. Cold season grasses need to be aerated and overplanted in late summer and early fall. In contrast, warm-season grasses need to be aerated and re-seeded in late spring and early summer.