Lawn Aeration for a
Greener, Thicker, Healthier Lawn!
Do you
need Lawn Aeration?
If you live in Topeka, the answer
is probably YES! One way to check for soil compaction (and,
therefore, the need for core aeration) is to push a
screwdriver into the ground up to the handle (about 3-4
inches). If this can be done without much pressure, you
probably don't need to aerate. If you find that lawn
aeration is necessary, lawn aeration is the best method.
Spike aeration (popular in the 1950's) is not recommended because while you create a
hole, you are compacting the surrounding soil.
Another way to
test if you have clay based soil (almost all of northeast Kansas) and a
compaction problem is to grab a handful of moist soil and
squeeze it together. If it sticks together your soil needs lawn
aeration. If it falls apart you have a loam based soil and do
not need lawn aeration.
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What is
Compaction?
Compaction is the pressing together of soil particles,
which squeezes air out of the soil. Most compaction occurs
in the upper two inches of soil. The biggest cause of
compacted soil is activity on soggy turf. Other causes
include watering lawns and/or excessive tilling when
preparing a seedbed. Construction and grading equipment used
to build homes also has adverse effects.
Causes of Compaction
| Children
Playing |
Upper 1 inch
of soil |
| Dogs |
Upper 1 inch
of soil |
| Sports
Activities (volleyball) |
Upper 2
inches of soil |
| Parking Cars
on Lawn |
Upper 3 inches of soil |
As soil is
compacted, the soil’s aeration process becomes ineffective. Air
spaces are squeezed out and filled with water. At this point,
the soil is waterlogged and unable to drain. Waterlogged soil
promotes shallow root growth. Compacted soil results in turf
with low energy, poor growth, and thin yellow-green
characteristics. It will not hold up well to traffic or weather
stress. Playing on it would tear the turf more quickly than
under normal conditions. Heat stress also causes the yard to
wilt sooner. Under any of these conditions, recovery takes
longer than it would for a healthy yard.
 More Benefits
of Lawn Aeration
Aeration loosens compacted soil and breaks up thatch. It allows
water and other nutrients to seep into the soil, encouraging new
root growth and establishing a stronger, deeper root base for a
lusher, healthier turf. Another benefit of aeration is the
reduction of water runoff and puddling.
By removing cores
of soil, aeration provides space for roots and soil to expand,
reducing further compaction. Aeration is also a method of thatch
control, because the microorganisms brought to the surface of
the lawn help break down thatch. All of these factors help the
turf establish a deeper root base, making the lawn more heat-
and drought-stress tolerant. (K-State Horticulture Report)
Lawn Aeration
permits the root system to go deeper where the ground
temperature is cooler and moister, allowing the grass to stay
greener longer in the heat of the summer. Remember, 90% of grass
is in the roots!
A healthy root
system is a must for an attractive lawn. Oxygen in the soil is
vital for healthy roots. Root growth is inhibited by clay and
compacted soils because of a restricted oxygen supply. Aerating
improves rooting and problem soils by allowing air into the
soil. An aerator does this job mechanically without destroying
the turf.1
- Healthy
roots are necessary for healthy lawns.
- Roots make
up 90 percent of the grass plant.
- Roots take
in oxygen and give off carbon dioxide.
- Restricted
air movement into the soil reduces health and vigor of the
turf.
- Aerating
equipment mechanically improves the movement of atmospheric
air into the soil and carbon dioxide out of the soil.
Is raking up
the plugs or cores necessary?
Most lawn care services and experts will tell you it is not
necessary to rake up the plugs after aeration. The plugs
will break up after a week or two. The next time you mow,
you'll break up most of them, and nature will do the rest over a
short period of time. Even though these soil remnants may look
temporarily unsightly, the plug method is considered more
effective because of this exchange of materials: Soil below the
surface is brought up to the top, where it’s left to decay on
its own and its nutrients gradually seep back into the ground,
while water and fertilizer from above ground are brought down
into the soil, where they’ll benefit grass roots.
However, other
experts at agriculture universities believe you should rake up
the plugs or cores if you have really poor soil. (Be aware
this could require all day or weekend depending upon your yard
size and ability.) If you do rake up your aeration plugs, remove
as much thatch as possible and place it in a compost bin so you
can return the compost as top dressing the next time
lawn aeration is done. For really poor soil, you may not want these
"cores" to dissolve and fill in the holes you just made in your
lawn. You want the holes in your lawn to be filled in with
new organic matter in the top dressing you apply. This way, your lawn's
root system can begin to take advantage of the beneficial
bacteria and microorganisms that are in the top dressing. Your
organic matter should be much softer than the compacted poor
soil just removed. The holes in the lawn give the roots area to
expand. This will help the entire surface of the lawn to absorb
water and fertilizer, while minimizing puddling and runoff.
After you
rake up and remove the cores and thatch, fertilize your lawn as
you normally would. Then spread a thin layer of top dressing
over the entire surface of your lawn. Be careful not to
completely bury and suffocate your lawn, while keeping in mind
that you do want enough top dressing so that when you rake it in
all directions repeatedly there is enough to fall into the
holes. When you finish raking you should still see plenty of top
dressing on the lawn surface, but the blades of the lawn should
be predominately showing through. You'll may have to experiment
in a small area until you get the hang of it. Finally, water
thoroughly, as this will continue the gradual process of working
the top dressing down into the lawn's root system.
How often
should I aerate my lawn?
Homeowners should aerate their lawns in the fall when over
seeding or applying fertilizer and in the spring for the first
three years. There after, once a year in the fall when the soil
is conditioned. Most lawns in Topeka
have compacted clay soil which restricts the movement of air and
soil to the roots. Unlike garden soil, the soil under lawns
tends to compact readily because unlike that of garden soil it
is never turned or worked with. For the lawn, aerating is an
alternative to tilling.
Good drainage is
one of the keys to having a healthy lawn, but all too often
our lawns in Topeka are growing on heavy clay soil that
packs down easily just with normal lawn use making drainage
a real problem.
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