Aeration, also called core cultivation, is an important part of any lawn restoration program. Aeration allows grass roots to penetrate the soil deeply, helps fertilizer and organic matter get to the roots, allows oxygen to reach the roots, and makes it easier for water to soak into the soil.
Aerate your lawn once a year in the fall. Avoid aerating during dry summer months because you may damage an already stressed lawn. Also, avoid periods when weed seeds are prevalent to prevent further weed infestation.
Aerators penetrate your lawn best when the soil is moist. Unless it rains, water your lawn a day before aerating. When aerating, make several passes in several directions over every square foot of your lawn. Next, break up all the plugs extracted by the aerator using the back of a rake or by dragging a metal-mesh doormat or section of chain-link fence over the plugs to spread the soil. You can also mix the soil from the plugs with the top-dressing you added while increasing the organic matter and microbes in your soil. Once you finish aerating, water your lawn thoroughly.
To soften the soil and allow for better penetration by the aerator, thoroughly water your lawn one or two days prior to aerating (the equivalent of 1-inch of rain). If you are aerating after prolonged rainfall, it is important to wait (at least a full day) until the soil has dried somewhat so that soil cores do not stick in the aerator’s hollow tines.
Manual aerators allow you to do small areas a little at a time and to aerate corners and other tight areas difficult to reach with large equipment. You supply the power for these tools by pushing the hollow cylinders or corers into the turf—just as you would push in a spade. The tool cuts a plug, or core, that is extracted and deposited on the lawn the next time you push it into the turf. A manual aerator does a good job but takes a lot longer.
Avoid aerators that only poke holes in the lawn without removing plugs because they are of less value to your lawn.
Small power aerators work similarly and are available at rental stores. Some machines use a rotating, tiller-like action that pushes the corers into the soil and extracts small plugs as the machines pull you forward. These lawn mower-size machines will fit into a full-size station wagon, minivan, or pickup truck, and requires two people to transport them.
The largest aerators require a truck and several helpers to transport them, but they do a better job. With these machines, the corers are vertically plunged into the turf to extract a sizable plug. You may want to have a pro tackle this job.
Contrary to popular belief, wearing golf spikes while working in the yard is not a great way to aerate your lawn. The spikes on golf shoes are less than ½-inch and are not long enough to penetrate the soil and reach the roots.