Most home owners know the lawn care basics of mowing, seeding, fertilizing and watering, but many forget the importance of aeration. If you want to create and maintain a lawn that stands out in the neighborhood then you also need to aerate the soil.
In order to achieve the most beautiful lawn your soil is capable of producing you must ensure the proper nutrients can reach and enrich the soil that feeds your grass. Aeration can really help you maintain a healthy lawn because this simple process allows much needed oxygen and water to seep through the upper soil layers and better penetrate the built-up lawn thatch or compacted soil.
- What is Aeration
- Why Aerate a Lawn
- Best Time to Aerate Your Lawn
- Best Way to Aerate Your Lawn
- After You Aerate Your Lawn
What is Aeration
Aeration is just a fancy word for breaking through thatch on your lawn and/or breaking up old compacted soil. This is achieved with an aerator tool or garden fork. It is sometimes referred to as “spiking”.
For convenience there are modern powered mechanical aeration tools that do the job much quicker and much better than you could using manual tools such as a fork.
Why Aerate a Lawn
Beautiful lawns are created through diligent work and require upkeep.
If you want to keep your lawn looking the very best it can possible be then you will need to go beyond simply mowing and watering it.
Aeration is a key process that is simple in execution but vitally important in it purpose.
Aerating your lawn is necessary so much-needed nutrients, air and water can break through thatch build-up or compacted soil to get to the grass roots in the turf.
Many people are unsure if they need to aerate their lawn so here are a few tips to help you determine if you need to be digging out your aerator tool.
Combating Thatch & Breaking-up Compacted Soil with Aeration
The more healthy your lawn is the more grass it will produce and this in itself can cause problems if you do not tend to this grass as it dies and is replaced with new blades.
This cycle of death and renewal produces thatch that stops nutrients, air and water from reaching the grass roots in the soil.
If you have a lot of build-up of thatch then this needs to be removed if you want your lawn to stay healthy and vibrant.
If the ground has dried out and has a spongy feel this can be a sign that your garden has an excessive thatch problem.
To identify if your lawn is suffering from excessive thatch take a shovel and remove a piece of the lawn down to a depth of about 4 inches. If there is a layer of thatch that is greater than 1/2 inch, aeration is needed and dethatching is highly recommended.
More on dethatching later (also known as scarifying).
Aerate to Reduce Harmful Effects of Heavy Lawn Use
If your garden lawn gets used a lot then chances are it needs aerated.
People and animals who walk on the ground contribute to soil compaction and thatch.
So, if you have a well-used lawn then you will most probably need to aerate it.
Dry Climates Lead to Compaction
If you live in a very warm climatic area where your ground tends to dry out very quickly, or you have moved to a new home where the garden has obviously been allowed to dry out, then chances are you will need to aerate.
Soil compaction is a big reason for nutrients, air and water not reaching grass roots.
Aerating Helps Remove Pests & Pathogens While Encouraging Compost
When thatch becomes a problem below the surface soil this deeper layer of old materials harbors organisms that are harmful to healthy grass and flower growth.
It can also help disease pathogens, such as fungal spores, to take root and thrive.
In addition to combating pests and pathogens aerating helps earthworms better navigate the soil to perform their compost activities and that can only end up in richer soil and healthier grass and plant growth.
Aerating Your Lawn Stimulates New Root Growth
Aerating your lawn also helps to stimulate healthy root growth by providing the roots with a more porous and easy to navigate environment.
Best Time to Aerate Your Lawn
Although there are specific times of year that serve as the best time to aerate your lawn as a rule-of-thumb you should aim to aerate when the soil is moist but not overly wet.
You should also avoid aeration when the soil is very dry unless its the first time you are tending to the lawn – after that in the following years make sure you aerate at the correct time of year.
The best time to aerate your lawn is during growing season.
Aerate During Growing Season
By far the best time for aeration is during the growing season.
Because when you spike the soil and allow nutrients, air and water access to the grass roots the grass has a better chance of growing quickly and evenly throughout the lawn. Lawn recovery is much quicker at this time.
You will also find that many patches areas will start to be repaired after aeration and you can help this along by planting new seeds which will stand a much higher chance of sprouting in the aerated soil.
You can use a pull behind core aerator or similar equipment that attaches to a riding mower with appropriate attachment and/or flat spike slitting (also know as chisel tining) aeration equipment to fully aerate your lawn during this period. This type of equipment is not recommended if you aerate out of season.
Cool Season & Warm Season Grass Aeration
Ideally, you should aim aerate a lawn that has cool season grass in the early spring or early fall.
If you have planted your lawn with warm season grass then you should aim to aerate your lawn in the late spring.
If You Need to Aerate Out Of Season
Though it is not ideal to aerate your lawn in very dry or very wet months we realise that sometimes this is just a plain necessity.
So if you need to aerate out of season here are some tips:
Aerating on Very Dry Soil
Usually during the warmer months the soil will be dryer and much more compacted. So, using an shallow spike rounded aeration tool you can spike between 2″ an 6″.
This shallow rounded spike aeration will allow water to get deeper into the soil and reach the roots without running the risk of damaging the lawn through cracking due to the heat.
A simple garden fork or spiked aerator shoe are more than adequate for this work.
Aerating on Very Wet Soil
Again this is not an ideal time to be aerating your lawn but if you have little choice in the matter then as with dryer soil you should avoid slitting by using a rounded spike aerator tool.
Use a shallow round spike that goes no deeper than about 6″. This will allow for proper drainage and will help raise soil temperature without running too much of a risk of creating mud patches.
By using shallow rounded spikes you will also avoiding turf damage that would probably occur if you used slitting (a flat spike) or powered equipment; frost can get into the slits and force them wider causing havoc on your lawn.
Ideally you should really try to avoid aeration during the cold months altogether.
Is Annual Aeration Necessary?
Aerating your lawn every year may not be a necessity for you. It really depends on the grass type that is on your lawn.
There are numerous low thatch grass varieties growing on the average American lawn and it is a good idea to identify the grass on your own lawn.
However, aerating your lawn annually will certainly do no harm to your lawn and can only bring benefits (as long as you do it right).
Best Way to Aerate Your Lawn
The best way to aerate a lawn is to use an aeration tool.
If you have the time and don’t mind putting in the work the most cost effective aerating tool is an aerating fork.
You can also use a standard garden fork though we don’t recommend it. Using a standard garden fork can sometimes cause additional compaction in the areas around the spike holes.
For this reason it is best to get a proper plug aerator tool rather than a solid tine spike aerator (unless you are aerating out of season – see section above). This is explained below.
You can use modern powered aeration machinery or you can aerate your lawn by hand.
However, regardless of which approach you plan to use there are 2 main types of aerating tool:
A spike aerator (solid tine).
With a spike aerator, you simply use the tool to poke holes into the ground with a solid tine, or fork.
These can come in 2 types:
- Flat spike.
- Round spike.
Only use a flat spike solid tine aerator during growth season or you run the risk of damaging your lawn (see section on aerating out of season above).
A plug aerator (hollow tine).
Plug aerators are hollow tine that actually remove a core or plug of turf from the lawn.
When you are aerating at the correct time of year be sure to use an aerating tool that uses hollow tine and that actually removes plugs of soil.
Poking holes in your lawn is less effective and can actually cause additional compaction in the areas around the holes as we mentioned earlier.
The only time this is not appropriate is when you are aerating very dry or very wet soil and when you are aerating out of season when excessive heat and dryness or excessive cold and frost could cause the plugged areas to widen thus creating more problems.
This is why we strongly advise you to avoid aerating during the very warm/dry months and the very cold months.
Go for an aerating tool or aerating machine that removes soil plugs at about 2 to 3 inches deep and 1/2 inch to 3/4 inch in diameter. Each plug should be no more than 2 to 3 inches apart.
Now you know the best way to aerate your lawn you may want to jump out to your garden and begin the process but before you start punching holes in your lawn there is one thing you may want to consider.
Consider Scarifying/Dethatching Before Aeration
If your lawn has a lot of thatch it will be a good idea to scarify it before you aerate it. Scarifying is also known as dethatching.
You can get an all-in-one powered dethatcher and aerator. On the plus side these combo machines work great and can save you a lot of time and manual effort.
Of course on the downside you may not be financially prudent to make such an investment if you only aerate your lawn once a year or less. But, if you have the spare cash we recommend it.
After You Aerate Your Lawn
If you opt for a plug aerator (which you should) then leave the soil plugs in place to decompose after aeration.
Just as mulching grass helps feed your lawn with much-needed nutrients, as they decomposes these soil plugs also help maintain the health of your lawn. Each plug will contain microorganisms that are released as the plug decomposes and they will digest the thatch and break it down for you.
All you have to do is mow the lawn as usual and the mower will break up the plugs or you can rake them once they have dried out.
You can seed and use fertilizer on your lawn immediately after aerating and should definitely seed any patchy areas on the lawn that you have treated with aeration. Consider overseeding.
Many people believe that you need to add a layer of topsoil at this stage but for a standard lawn it is certainly not essential and can add unnecessary expense.
However, for lawns that are heavily compacted or have deep thatch you should consider covering it with about 3/4 of an inch of compost making sure you rake it evenly so the plug holes are filled. Again, if your lawn does have heavy thatch you should scarify/dethatch it first.
Sometimes plug aeration can bring up weed seeds from the lower soil levels and these will thrive in the newly aerated soil. Thus the soil may need treated with a herbicide, though not necessarily – if your lawn has no real history of weeds you can probably skip this step.
For cool season grasses use a preemergent herbicide in the spring following a fall aeration or in the fall following a spring aeration.
For warm season grass apply the herbicide the fall after aerating.
Do not use a herbicide at the same time you reseed or you will kill the grass seed with the weeds. Give yourself plenty of time between herbicide application and reseeding.