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
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
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.