The Best time to Aerate and Overseed a lawn is in early spring and late fall, with temperatures averaging 55-70 degrees.
Aerating your yard during these two seasons will result in a vibrant, healthy, green lawn, allowing the grass to become more durable and withstand summer’s hotter temperatures and heavy traffic.
How often should you aerate a lawn? It is essential to aerate your lawn at once (or ideally – twice) a year – because compacted soil creates a lot of stress on the root system and potential growth of any lawn.
Compacted soil hinders the ability of grass to absorb the nutrients required for growth by preventing needed water, oxygen, and nutrients from reaching your lawn’s roots.
Aeration also breaks up the soil, allowing much-needed oxygen and water to enter the lawn easily.
Step #1 – Choose the Best Time To Aerate and Overseed Lawn
The best time to oversee a lawn is right after doing lawn aeration. The Best Time To Aerate a lawn is in Spring (after last thaw) and in the Fall (month or more before the first frost).
Lawn aeration (especially core plug aerators) creates the perfect conditions for planting and growing grass seed.
By opening core holes in the lawn through aeration – you have provided essential water, oxygen, and nutrients to reach and jump-start new grass seeds.
When and How To Aerate Lawn
Now that you know the Best Time to aerate a lawn and How Often(once or twice annually) let’s take a look at the three most important steps on How To Aerate a Lawn:
Step #1 – Choose “Spike or Core Plug” Aeration Method
Whether you are renting or planning to buy new aeration equipment, you’ll need to decide which type of lawn aeration equipment to use.
Spike Aeration Equipment:
Spike aerators can be used with manual (push) aeration equipment. However, better spike aeration equipment is the “pull-behind” type, often pulled with a riding mower.
Spike aerators operate by plunging 2-3″ Long Spikes into the lawn, creating small diameter holes in the soil.
Compared to core plug aeration, spike aeration forces spikes into the ground, loosening the soil and providing space for lawns to receive water, oxygen, and nutrients.
Depending on your budget, we recommend considering Core Plug aeration as the best lawn aeration method instead of spike aeration.
Core Aeration equipment
Core aerators plunge core inserts (2 -3″ deep) into the lawn, removing small plugs from the soil. This type of equipment is connected and pulled behind a riding mower or small tractor.
The Core aeration-cutting method does not compress the soil around the opening like spike aeration can, and the plugs pulled out of the ground can be left on top to feed the lawn.
Read this article from Best Home Gear to learn How To Use a Lawn Aerator before you begin.
Step #2 – Water Lawn Day Before Aeration
Compacted soil makes it difficult for water to absorb effectively into the lawn before evaporating. Sufficient watering will loosen the compacted dirt making the yard more receptive to lawn aeration.
This step will also allow the soil to shift, freeing up the roots and allowing them better access to existing nutrients.
Heavy watering the day ahead of aeration, especially in arid regions where dry conditions seldom allow water to saturate the ground before being lost to evaporation.
Be sure to water the lawn the day before you aerate for optimum aeration, softening the soil before you begin lawn aeration.
The rule of thumb before aerating a lawn is to provide at least an inch of water to ensure the area is thoroughly hydrated.
Step #3 – Flag Underground Sprinkler Heads
Important: Be sure to “flag” every Sprinkler Head in your underground irrigation system. Leave flags in place before and during lawn aeration. Lawn aeration equipment has tines or spikes that are 3″ or longer and will damage sprinkler heads if they come in contact with any sprinkler head.
Step #4 – Lawn Aeration
Perform Lawn aeration, by following traffic directions similar to your mowing patterns. NOTE: Leave plugs or other lawn debris from lawn spike or plug core aeration – On the Lawn. This will be taken care of in Step #6 Below.
Step #5 – Overseed Lawn
Should you overseed a lawn before aeration? That would be a Big “NO”. Once the lawn is aerated, it has holes to allow new grass seed to penetrate the ground, instead of laying on top of the soil.
Start overseeding, by selecting a grass seed that closely matches your existing lawn (ie; Kentucky blue, Rye, etc.) use a broadcast spreader to spread grass seed across your entire lawn.. Spread new grass seed according to recommended settings, using a broadcast spreader.
Water the grass seed every day (30 minutes) or every other day (one hour) for 7 days to allow the grass seed to germinate.
Step #6 – Mow or Rake Core Plugs Into the Lawn
Now that you have Aerated and Overseeded the lawn, it is time for our final step.
It’s time to Mow or Rake the plugs back into the top layer of grass. This process serves several purposes;
- Once the grass plugs dry out, they will crumble and be absorbed through the top layer of soil.
- Secondly, the core plugs contain vital nutrients that will feed your lawn.
While some will recommend Raking all the core plugs up and disposing of them, we recommend allowing the core plugs to dry out for a few days, then mowing (after overseeding) them with a low-height setting mulching mower – sending them back into the soil.
By mowing Aerated core plugs into the lawn after overseed, you will provide a fine layer of soil – and keep “New” grass seed moist while it Germinates
VIDEO – HOW TO AERATE and OVERSEED LAWN
Lawn Aeration Tips to Remember:
Tip #1 – Bury New Irrigation Lines Deeper
Lawn aerators vary in depth, with most core aerators ranging between two and three inches deep. Spike aerators may penetrate the ground slightly longer.
If a homeowner has irrigation lines or plans to install a sprinkler or irrigation system on the property, they must account for the lawn aeration process.
Typically, when installing irrigation lines, professionals set them between 10-12″ deep, laying them deep enough not to be cut or penetrated by the spikes and coring tools used in lawn aeration.
We recommend burying the irrigation lines at least 10″ deep, as this depth will prevent damage to the irrigation system and eliminate the risk of flooding the lawn.
Tip #2 – Flag ALL Underground Sprinkler Heads (See Step #3 Above)
Tip #3 – Avoid Spike Shoe or Manual Aeration
While some rely on spike shoes or manual hand aerators, they have little effect on the proper or full aeration of your lawn.
Shoe aerators are spikes attached to your boots or shoes that penetrate the ground as the person walks across the lawn.
While they do put holes in the ground, that is mainly where their benefit stops. The main problem with spikes is the compression of the dirt around them. With shoe aerators, the end compresses the soil, as does the weight of the person wearing the shoes.
Just as ineffective is the use of Manual Aerators. Manual aerators come with a long handle and spikes attached at the bottom, which cover very small areas of lawn at a time.
However, one exception is the Yard Butler aerator, which removes core plugs from the lawn.
While the Yard Butler tool is effective, its design is intended for very small lawns.
Tip #4 – Don’t Aerate Lawn In Summer
Summer is a season in most climates that can create great stress on lawns.
With high temperatures and occasional droughts, grass can struggle to survive.
The last thing you want to add to lawn stress is aeration, which can risk exposing the roots to drying out—the kiss of death in lawn care.
Regardless of which method you choose to aerate your lawn, the importance of lawn aeration should not be overlooked.
Soil, by nature, becomes compacted over time. Additionally, lawns can become overly thick, preventing water and nutrients from reaching the roots where the feeding occurs.
Everyone can do their lawn a huge favor by setting up a lawn aeration schedule.
Ideally, the schedule should be in early spring or late fall (or both), with ideal temperatures ranging between 55-70 degrees. The result will be one of the best-looking healthiest lawns on the block!
References & Further Reading:
- Proper Aeration of Turf Grass – PennStateUniverity.edu
- Improving Soil Conditions – MichiganStateUniversity.edu
- Check out why you should aerate your dry lawn here- Gardenersworld.com