The answer to 'frequency of aeration' is that most experts recommend aerating your lawn once a year, typically in the fall. Aeration is the process of punching small holes in the soil to allow air, water, and nutrients to better reach the grassroots. This helps to alleviate soil compaction and promotes a healthier, greener lawn.
The ideal time to aerate is when the grass is actively growing, so fall is the best season for most climates. This allows the lawn to recover and the holes to fill in before the winter dormancy period. Aerating in the spring can also be beneficial, but it's important to avoid doing it when the soil is wet or the grass is just starting to green up.