When you sit on your lawn you probably think that the only thing between you and mother earth is a few blades of grass.  What you're probably not seeing is the thatch beneath the grass.  Thatch is a layer of dead vegetation, dirt, gravel, and dust beneath your grass. 

The thatch on your lawn can be your biggest hindrance in growing a vibrant and healthy lawn.  A thick thatch can prevent water and essential nutrients from reaching the soil, and the result is a lot of your time and effort wasted for a minimal result.  Luckily, there are several ways that you can reduce the amount of thatch present in your lawn and thus make it easier to keep your lawn healthy.  The three most common (and arguably the most effective) methods are Aeration, De-Thatching, and Power Raking. 

Aeration is when a machine takes cores out of your lawn that are between 3 to 5 inches long.  These are the little dirt cores that you probably threw at your friends when you were kids.  When you aerate your lawn you are creating more physical space for water and nutrients to entire the soil, as well as creating more room for the grass to spread its roots.  Aeration is no more expensive than a Power Rake and is arguably more effective and less damaging. 

De-Thatching your lawn is much more invasive than a Power Rake or Aeration but it does remove a much larger amount of thatch.  A blade is set low to the soil level and physically rips out the thatch.  As you can imagine this process can be very damaging to grass growth.  For this reason this is best performed in the very early spring or late summer. 

Performing a de-thatch in mid-season will inhibit growth and perhaps even kill off parts of your lawn.  An aeration is recommended when you are late into the spring season. 

Power Raking is very similar to a De-Thatch except that the blades are set shorter so that they do not intrude on as much of the soil.  Instead of ripping the thatch out the blades slice it out.  The result is less effective compared to a De-Thatch or Aeration, but less damaging to the soil as well. 

Power raking is similar to a de-thatch in its execution, however, and should not be done during the middle of the season.  It can actually do more harm than good to healthy, growing grass. 

All three processes make it easier for water and nutrients to reach the soil, and all three can be performed by the homeowner with rented equipment or professionally for a marginal cost.  It is recommended that you leave it to the professionals to ensure that it's done properly, but by no means is it impossible to be done by yourself.  If you're a handyman (or woman) taking the time to do it right is all you need.  

Have fun!