The steps to aerating a lawn are to mark the sprinkler heads, water the lawn, aerate with a mechanical aerator, rake dried soil plugs, and apply compost, seed and fertilizer. A year after the establishment of new seed or sod, it is best to aerate lawns annually.
It is important to mark sprinkler heads in advance of aeration because mechanical aerators can damage sprinkler heads. Loosen the soil in advance of aeration with an irrigation system or sprinkler. Applying a minimum of one inch of water allows the machine to effectively remove soil plugs.
The most practical, cost-effective option for aerating a lawn is to rent an aerator from a local hardware or home improvement store, according to Bayer Advanced. In sandy or well-aerated soils, one pass with the machine is sufficient. Aerate lawns that are in poor health or you haven't aerated in over a year with a second pass set at an angle to the initial pass.
After using the machine, it is best to let the soil plugs scattered on the lawn dry out. Once dry, running the plugs over with a lawn mower or raking them typically breaks the plugs up. Keeping the plugs in the lawn allows beneficial organic matter and microorganisms to remain in the soil.
Finally, apply fertilizer, grass seed, and a thin layer of compost to the lawn to reinvigorate the soil and reestablish the turf canopy.