What is aeration?
Technically speaking, aeration is the naturally occurring process of air exchange between the soil and its surrounding atmosphere. Practically speaking, aeration is the process of mechanically removing small plugs of thatch from the lawn to improve soil aeration, creating holes. These holes allow more air and water circulation around your lawn's roots, preventing fungal invasions, and they encourage the growth of healthy microorganisms in the soil. These microorganisms eat lawn thatch, a layer of dead bits of grass on top of the soil that can choke out your lawn. Aeration also makes it easier for your lawn to grow stronger, deeper roots. A good root system is essential for your lawn's survival in times of drought.
How do I know if I need to aerate?
New home: In most home lawns, the natural soil has been seriously disturbed by the building process. Fertile topsoil may have been removed or buried during excavation of the basement or footings, leaving subsoil that is more compact, higher in clay content and less desirable for healthy lawn growth. These lawns need aeration to improve the depth and extent of turfgrass rooting and to improve fertilizer and water use.
Heavy traffic lawns: kids, mowing, pets, etc. Intensively used lawns are exposed to stress from traffic injury. Walking, playing and mowing are forms of traffic that compact soil and stress lawns. Raindrops and irrigation increase soil density by compacting soil particles and reducing large air spaces where roots may readily grow.
Clay soil: Compaction is greater on heavy clay soils than on sandy soil, and it is greatest in upper 1 to 1-1/2 inches of soil. Aeration helps heavily used lawns and lawns growing on compacted soils improving the depth and extent of turfgrass rooting, allowing better water uptake, enhancing fertilizer use, and speeding up thatch breakdown.
Thatch buildup, or lack of healthy turf: Most home lawns are subject to thatch accumulation. If thatch is left unmanaged, it can lead to serious maintenance and pest problems. For example, thatch accumulation of more than ½ inch on Kentucky bluegrass lawns impedes water and fertilizer effectiveness. Core aeration reduces thatch accumulation, minimizes its buildup and modifies its makeup by incorporating soil into the thatch. As soil is combined with the thatch debris, soil organisms are better able to break down the thatch and reduce its accumulation.
Water runoff and puddling issues: Due to soil compaction water cannot filter through the soil, and water stays on the surface of the lawn for a longer period of time. Aeration loosens up the soil and allows for the water and nutrients to reach the roots of the turf.
What does aeration do for my lawn?
- Improves air exchange between the soil and atmosphere.
- Enhances soil water uptake.
- Improves organic fertilizer uptake and use.
- Reduces water runoff and puddling.
- Improves turf grass rooting.
- Reduces soil compaction.
- Enhances heat and drought stress tolerance.
- Improves resiliency and cushioning.
- Enhances thatch breakdown.
When do I aerate?
Because the aeration process is stressful on lawns, it should only be done during periods just before active growth is expected. For cool season grasses, those typically found in the northern half of the country, this would be in early spring or early fall, the 2 times of the year when cool season grasses really grow. During the hot summer months, cool season grasses really slow down in the growing department and this is not a good time to be aerating. If you're planning on aerating in the spring and you plan on using a crabgrass control product, you'll want to aerate before the pre-emergent application is made, which is as a rule around the time when forsythias first start blooming. Overseeding in cool-season areas, will fill-in bare or thin spots and help build a thicker lawn faster. The new seed quickly takes root in the freshly aerated lawn and provides new life to your already established grass. As your lawn gets thicker and healthier, your new grass plants help reduce the chance of new weeds sprouting.
How often should I aerate?
Once a year is ideal for properties. Lawns with high clay content should be aerated twice a year. If you are on a good maintenance program, with organic fertilizing we can do an annual analysis each year in the late winter/early spring and late summer/early fall to see if aeration is necessary.
What is the aeration and over-seeding process?
Immediately after aeration, your lawn will be dotted with small plugs pulled from the soil. Within a week or two, these small plugs of thatch and soil 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. These roots are a sign that the turfgrass is responding to additional oxygen, moisture and nutrients in the soil from the aeration process. 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 signs of wilt. With repeat aerations over time, your lawn will show enhanced heat and drought stress tolerance. Don't expect miracles from a single aeration, particularly on lawns growing on extremely poor soils. Most lawns benefit from annual aeration. Lawns that receive this care will be healthier, more vigorous, easier to maintain and have fewer pest problems than lawns that are neglected.