Just like lawn dethatching and lawn rolling, I can see why you might think aerating a lawn with a lawn core aerator is necessary or even beneficial on an annual basis.
Not only is it often recommended gardening advice, but most lawn care companies do this as part of their regular service, organic gardening companies included.
The thing is, it can be beneficial if done right, but it generally isn’t done right, so I'm going to give a few lawn aeration tips here.
Aerating a lawn involves cutting round holes in the soil with a lawn plug aerator and pulling the core out. It can be a good thing, but only if followed by another important practice.
As an important aside, there is another method called spiking that makes holes in your nice organic soil without pulling any soil out. You may have seen those shoes with spikes on the bottom you can wear while walking on the lawn. This method is useless because although it is creating pore spaces in the soil, it is compacting the surrounding soil. Soil must be pulled out to get any benefits. So onto the lawn aeration tips.
The reason lawn aeration with a lawn core aerator is generally done is because it is thought to increase air and water penetration into the soil. While these are important organic gardening goals and it works for a very short time if enough cores are pulled from the soil, the effects are short-lived.
Here are the 3 biggest downsides:
Aeration should not be necessary on an organic lawn that is healthy, but while you are in the process of transitioning your lawn to be healthy and perhaps moving to organic gardening methods, it can be very useful to create a healthier, less compacted soil environment and a denser, healthier root system.
All this will happen only if the tines are sharp, if the machine actually pulls cores out of the lawn, if it is done at the right time of year, and if it is followed by another practice.
The right time of year is generally fall, although early spring is okay, too. The other practice is discussed next and it is lawn top dressing.