Removing small cores of soil from your lawn reduces soil
compaction and promotes root growth for healthier grass!

What is Aeration?

Technically speaking, aeration is the naturally occurring process of air exchange between the soil and its surrounding atmospheres.   
Practically speaking, aeration is the process of mechanically removing small plugs of thatch and soil from the lawn to improve natural soil aeration.  
It's commonly called "core aeration" in the lawn service industry, and you may have heard of it as soil cultivation (coring, spiking and slicing).  
Most homeowners simply call it aeration.

What Are The Benefits of Aeration

Core aeration can help make your lawn healthier and reduce its maintenance requirements through these means:

    Equipment Affects the Outcome

    The type of aeration equipment can determine how effective the treatment will be.  In general, turf responds best when core holes are close and deep.   Equipment with hollow tines removes soil cores.  Equipment with open tines divots the soil surface.   Aeration equipment also varies in tine size up to 3/4 inch diameter and in depth of penetration up to 4 inches, depending on the manufacturer's specifications.

    Why is Aeration Necessary?

    In most home lawns, fertile topsoil may have been removed or buried during excavation of the basement or footings, forcing grass to grow in subsoil that is more compact, higher in clay content, and less likely to sustain a healthy lawn.

    Walking, playing and mowing will compact soil and stress lawns.  Raindrops and irrigation further compact the soil, reducing large air spaces where roots readily grow.  Compaction is greater on heavy clay soils than on sandy soils, and it is greatest in the upper 1 to 1-1/2 inches of soil.

    Aeration can help relieve soil compaction, allowing your grass to grow deeper roots and make better use of water and fertilizer.

    Relieve Thatch Accumulation

    Most home laws are subject to thatch accumulation.  Left unmanaged, it impedes water, fertilizer, and pesticide effectiveness.   Core aeration combines soil with the thatch debris, so organisms are better able to break down the thatch and reduce its accumulation.

    How Often Should Lawns Be Aerated?

    Most lawns benefit from annual aeration.   Heavily used lawns, or those growing on heavy clay or subsoils, may need more than one aeration each year.   Again, turf responds best when tine spacing is closer and penetration is deeper.

    When is the Best Time to Aerate?

    If you have cool season turfgrass such as Kentucky bluegrass and perennial ryegrass, both spring and fall are ideal times to aerate.  In spring, aerate between March and May.  Perform fall aeration between August and November.  Aeration before or at the time of late season fertilization enhances root growth and improves spring greenup and growth.

    Warm season turfgrasses such as zoyziagrass and bermudagrass should be aerated in mid-spring to summer.  Avoid aerating when warm season grasses are dormant - it may encourage weed competition.  In addition, avoid aerating warm season grasses during spring greenup, and not until after their first spring mowing.

    Herbicides, Fertilizers & Aeration

    It's best to aerate before you apply pre-emergence herbicides, rather than after.  Aerating after a herbicide application can reduce the chemical barrier formed by the herbicide, allowing weeds to germinate.  Applying fertilizer after aeration helps the lawn compete against weeds.  Water the lawn after aeration, particularly in areas where drought and high temperatures are common.

    What can you expect?

    Immediately after aeration, your lawn will be dotted with small plugs pulled from the soil.  Within a week or two, they break apart and disappear into the lawn.

    About 7 to 10 days after aeration, the aerification holes will be filled with white, actively growing roots - a sign that the turfgrass is receiving additional oxygen, moisture, and nutrients from the soil.

    On compacted soils and on lawns with slopes, you should see an immediate difference in water puddling and runoff after irrigation or rainfall.   After aeration, your lawn should be able to go longer between waterings, without showing sighs of wilt.   With repeat aerations over time, your lawn will show enhanced heat and drought stress tolerance.

    Remember, most lawns benefit from annual aeration.  And while you shouldn't expect miracles, especially with poor soil, lawns that receive this care will be healthier, more vigorous, easier to maintain, and have fewer pest problems.


    Technical credit: This brochure was written by Dr. Robert Shearman, horticulture professor at the University of Nebraska, Lincoln NE.

bulletImproved air exchange between the soil and atmosphere.
bulletEnhanced soil water uptake.
bulletImproved fertilizer uptake and use.
bulletReduced water runoff and puddling.
bulletStronger turfgrass roots.
bulletReduced soil compaction.
bulletEnhanced heat and drought stress tolerance.
bulletImproved resiliency and cushioning.
bulletEnhanced thatch breakdown.

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