One of the best things you can do for your yard is to regularly aerate it. When your soil becomes compacted, it becomes more difficult for your lawn to get the water and nutrients it needs. Hard, compacted laws do not allow much water to penetrate into the soil. The problem is even worse for yards that slope. Water runs off a compaced sloping yard rather than soaking into the soil.
Aerating the lawn involves using equipment that pulls plugs of soil out of your yard which relieves the soil compaction and allows water and nutrients penetrate the soil. Aerating frequency varies between yards. Some yards become compacted more easily than others and should be aerated two or three times a year. Other yards, especially those with sandy soil, may not need to be aerated more than once a year or even every other year.
You can buy an aerator, or you can usually rent a high quality lawn aerator at a local equipment rental center. Avoid using aerators that just poke holes in the yard with spikes. Plug aerators remove plugs of soil and leave them on top of the yard which loosens up the soil. Spike aerators don’t really loosen the soil because they don’t remove any soil. They can actually make soil compaction worse. Alternatively, you can have your lawn aerated by a good local lawn care service.
You can aerate any time during the year, but the best time is when your lawn is actively growing. Fall and Spring are usually the best times to aerate your lawn.