How to Aerate a Lawn. You've done everything right and still the lawn looks lousy, especially where the kids play and the dogs romp. Check your soil for compaction, then use a core aerator to pull out plugs of soil and let in air, water and fertilizer for an instantly healthier lawn.
Learn to recognize compacted soil: Water stands but doesn't sink in, fertilized grass doesn't green up, and affected areas actually look flatter than the rest of the lawn. The problem is worst in clay soil areas in times of weather stress.
Test the soil for fertilizer, lime or sulfur needs, and apply as recommended.
Raise your mowing height one notch.
Wait and watch for improvement for a month, then aerate manually or mechanically.
Look at a manual aerator - a handle on a T-bar with four hollow pipes that you plunge into the lawn to remove cores of soil. If your lawn is large or you have time and energy constraints, consider renting a mechanical core aerator.
Rent only equipment that you know how to operate safely. Ask as many questions as you need to before taking the aerator home.
Drench the lawn one day and use the aerator the next.
Walk back and forth across the lawn in a pattern that ensures that you cover each area only once, and leave cores where they fall.
Crush up the soil cores and add compost or peat moss if necessary to make enough mix to fill in the holes. Use your gloved hand or the back of a garden rake to fill the holes and make them level with the ground.
Fertilize once with a slow-release turf grass formula and resume your regular watering schedule. Avoid mowing for at least three weeks, or longer if the grass is slow to grow.