Core Aeration, Soil Compaction, Healthier Lawns
You have probably seen core aeration done on a lawn before but never realized what it was. After all, they could easily be mistaken for animal feces. Despite appearances, it's a regularly utilized strategy to keeping lawns healthy and looking beautiful.
What is core aeration?
Core aeration is a specific method of aerating your lawn that uses a lawn aerator machine with hollow tines to extract and pull out little "cores" (small cylinders that look like plugs, 1/2 inch to 3/4 inch) of soil and thatch (a layer of living and dead organic material that accumulates around the base of grass). By doing so, you dramatically increase the amount of water, air, and nutrients that can travel through the soil through these channels. It also reduces soil compaction and weed growth as their roots can't achieve a strong foothold in the soil.
Other aeration methods exist, but core aeration is generally the most effective of them. An alternative would be to use machines that drive solid tines into the ground, forcing soil downward to create holes as opposed to pulling them out. Similarly, one could take a pitchfork and pierce the lawn every few square inches, but this is generally not feasible and inefficient.
Why is core aeration necessary?
Soil is more than just a dense pile of dirt. Underneath your plants and lawns, a complex network of life-critical systems are at work keeping everything beautiful on top. For the entirety of it to remain healthy, every section of your soil needs sufficient and abundant access to water, air, and nutrients. These can only be delivered and propagated throughout the soil if the appropriate pathways are created. Compacted soil reduces the availability of these pathways. Similarly, thatch at the base of your grass makes soil more impervious and reduces downward flow of essentials into the roots of your grass and other plants.
How do I know when I need to aerate my lawn?
It may be a little unintuitive but it's relatively easy for a lawn to become compacted without your knowing. There's a high chance your soil is compacted if you've ever had any of the following situations: picnic on the lawn, kids and/or pets playing on the grass, machinery wheels (e.g. lawn mower), and more.
Some of it is also dependent on your region. If you live in a city where heavy coil soil is present, you'll likely need to aerate your lawn on an annual basis to prevent it from becoming weak, loose, and thin.
There are a couple other symptoms to look for:
If you suspect that your soil may be compacted, there's an easy "screwdriver" test you can perform to evaluate. Stick a normal household screwdriver into the soil with your hand. This should be performed with relative ease; if you meet the slightest resistance, your soil is likely compacted.
Aside from the soil, there may also be thatch that's making the soil impervious and needs to be removed. While dethatching and soil aeration are two fundamentally different processes, they are usually done in conjunction with one another. Even thatch that is only 1/2 inch thick can have profoundly negative impacts on the health of your soil and grass. Different grass types have different propensities for thatch build up. Usually, it's the grass types that spread aggressively (e.g. Bermudagrass in southern regions, Kentucky bluegrass in northern regions) that are most prone to thatch buildup.
When should I aerate my lawn?
Like most landscaping projects, the best time to aerate is right before your grass reaches its peak natural growth periods. If aeration is done during the active growth period, there's the possibility that the grass regenerates and recovers fast enough to fill in the holes resulting from aeration, rendering efforts obsolete. While a general aerating process is usually beneficial, it can be detrimental if done at an inappropriate time. One general rule to sticky by is to avoid aerating lawns that are dormant.
Warm-season grasses, usually found in southern regions, should be aerated between the late half of spring to the earlier half of summer. Cold-season grasses, usually found in northern regions, should be aerated during either the earlier half of spring or fall.
Aeration is also easier when the lawn is mildly damp and moist from a previous watering session or light rainfall. If the soil is soaking wet, it's best to wait a few days. On the opposite extreme, soil that is overly dry can also be tough to work with so adding some moisture may reduce the efforts necessary to complete the job.
How do I aerate my lawn?
There is a variety of aeration equipment that can be bucketed into 3 main buckets:
In general, it's always best to let a professional operate more complex machinery. However, it is possible for a homeowner to go to a local lawn and garden store that will rent aeration machinery. A simple way to understand the operation of these types of machinery is to compare it to a lawn mower - you'll move back and forth across your lawn in the appropriate patterns and directions.
What do I do after I aerate my lawn?
Once the job is complete, all matter and substances should be allowed to decompose where they fall. They'll break apart during the next sequence of yard work or natural occurrence whether it be rainfall or lawn mowing.
It is also beneficial to fertilize your yards and gardens after aeration. After all, one of the main reasons to aerate your lawn is to allow nutrients to spread easily throughout the soil. Fertilizing post-aeration is a great way to accelerate the growth and recovery of your landscape.