How To Aerate a Lawn
Over time the soil under your lawn becomes compacted. Soil compaction makes it harder for the grass roots to grow and reduces the absorption of water. Both of these problems cause a lawn to become stressed. When a lawn is under stress it tends to brown easily and is less resistant to disease.
Why Aerate a Lawn
In order to to reduce compaction, you must aerate the soil periodically. Aerating can be done by poking holes into the ground or by pulling plugs out of the ground. The latter method is preferred because it loosens the soil; while poking holes actually packs the soil tighter. However, either method is beneficial. By making holes, you enable more water to soak in and lets fertilizer reach the roots.
How to Aerate a Lawn
You can use a tractor with an aeration rig, but if you are like most people, you don't own a tractor. You can purchase shoes with long spikes or set of spikes on a handle. Both of these will take some time to cover your entire lawn. To make faster work of this task you can rent an aerator from a local tool center or you can hire someone to do it for you. Often the cost of a pro is little more than the cost to rent the tool, so do some checking first.
When to Aerate a Lawn
Sandy soils can be aerated just once a year. Clay soils should be aerated twice a year. Cool season grasses like ryegrass, bluegrass, bentgrass and fescue lawns should generally be aerated in the fall. Warm season grasses like Bermuda, Bahia, St. Augustine should be aerated in the late spring but before high heat or drought conditions set-in.
If you are going to aerate your lawn, it is the best practice to aerate before you fertilize, compost or seed a lawn.