The aerating process punctures the lawn through the roots and penetrates the soil to allow for improved oxygenation and nutrient transport, which eventually leads to new root growth 6-8 weeks later.
Is performed using an aerator. The machine itself uses a small combustion engine to drive the wheels and rotate the shaft on which the splines are located. Ballast weights, which are usually solid iron bars weighing 30-35 lbs each, provide the weight to force the splines down through the grass blades, roots, and thatch into the soil a few inches and pull out cylindrical-shaped "plugs" creating temporary voids in the lawn.
Because of the ballast weights and weight of machine itself given its relatively small size, the process can be very labor intensive and exhausting.
"Plugs" will be seen scattered on a lawn that was aerated recently...
It takes about 6-8 weeks from the time of aeration for the punctured voids in the lawn to fill themselves in naturally and grow additional roots.