Lawn Aeration

Many of us are familiar with maintaining a healthy lawn through proper mowing, fertilizing, irrigation, and weed and pest control. Another lawn care practice is aeration. Without it your other lawn care activities may not be as successful.

What is Aeration?

Lawn aeration is the process of creating holes in the lawn and is done mainly to alleviate soil compaction. Soil compaction occurs when soil particles are pressed together, collapsing the air pockets, and preventing the flow of nutrients, oxygen, and water to the grass roots. Just a layer of compacted soil 1/4 to 1/2-inch-thick can greatly affect the health of your lawn.

Aeration restores soil circulation so lawns can develop strong, deep roots to help them withstand stressful situations, such as heat and drought. Ideally, grass roots in healthy soil should grow anywhere from six inches to two feet deep, with some species growing much deeper.

Signs Your Lawn Needs Aeration

Not every lawn needs aeration, and it’s only recommended if:

• You’ve moved into a newly constructed home where the topsoil was stripped, and the lawn was established on compacted sub-soil.
• Your lawn experiences heavy traffic and use from vehicles and small equipment, children, pets, or social gatherings.
• You live in an area with heavy clay soil.
• Water forms pools in areas where it used to be absorbed or runs off onto sidewalks.
• Your grass looks stressed, is thin and patchy, or has bare dirt areas where even the weeds won’t grow.
• The soil is hard to pierce or dig into.
• You laid sod down on top of existing soil, creating a mismatch in soil density.
• Your lawn feels spongy and dries out quickly. This could be caused by too much thatch (layer of decomposing organic matter that forms between soil and grass).
•  To check, remove a slice of lawn about four inches deep with a shovel, and measure the thatch layer. A layer over 1/2-inch-thick acts like soil compaction, so aerate to revive your lawn. Dethatch first.
• Some grasses are more prone to thatch buildup and require regular checking, such as Kentucky bluegrass, Bermuda, and Zoysia grasses.

When to Aerate Your Lawn

The best time for aeration is just before or during the peak growing time for your type of grass. For warm-season grasses, the best time is late spring or very early summer. For cool-season grasses, the best time is early to mid-spring, or late summer to early fall. When aeration occurs during the growing season, the grass can recover and fill in the holes created by the aeration equipment.

If you applied a pre-emergent herbicide in the spring, you can still aerate your lawn. Research has shown that aeration does not affect weed prevention or crabgrass control.

Aeration does cause some root damage, so to avoid further stressing the roots don’t aerate during periods of extreme heat, drought, or cold snaps. Also, don’t aerate your lawn for the first year after it’s been newly sodded or seeded — you want to make sure the roots are firmly established.

If your lawn is growing well, and you have sandy soil, you can aerate every 2-3 years. But if your lawn gets a lot of traffic, or you have heavy clay soil or a grass type that forms thick thatch layers, you may need to aerate more often.

Types of Aeration Tools

There are three main categories of aeration tools: plug or core aerators, spike aerators, and slice aerators.

Plug or core aerators use hollow tines (plug spoons) to penetrate the ground and remove plugs or cores of grass and soil. This is considered the most effective aeration method for opening up the soil around grass roots.

Spike aerators use solid tines or forks to puncture the soil, forcing the soil out of the way around the hole without removing any of it. This can actually increase compaction around the puncture area. Spike aerators are best suited for looser soil that’s not too dense.

Slice aerators use rotating blades to cut narrow slits in the soil. They also leave the soil in the ground without removing it and are generally used for less-compacted soil.

Choosing the right aeration tool depends on your lawn size and soil condition. Some examples of aeration tools include:

• Manual walk-behind push aerators with either rotating blades or spikes. They work best for small and medium-sized lawns, especially those with obstacles such as trees. These aerators are not suited for heavy, compacted soil.
• Handheld aerators in both spike and plug models. These are the most affordable of all the aerators. They’re designed as either a single pole or a dual-handle grip high on the tool, with a foot bar to allow you to step on the aerator to drive the spikes or hollow tines into the soil. Aeration with handheld tools is labor-intensive and time-consuming, and best for small lawns or problem areas on lawns. The spiked ones are better for looser soils. Some people use a pitchfork rather than buy a special aeration tool.
• Tow-behind aerators come in all three types, and can be hitched to a riding lawn mower, an ATV (all-terrain vehicle), or a quad bike. They’re used mainly to aerate larger properties with wide-open spaces. You’ll have to load the aerator with some kind of weight (e.g. cinder blocks, bricks) to force the spikes, plug spoons, or blades into the soil.
• Walk-behind self-propelled core aerators. These are well-suited for small to medium-sized properties and are good for getting into narrow or sloped areas. Home owners can rent these machines from lawn and garden stores or home improvement centers.

How to Aerate Your Lawn

Many landscape companies offer aeration services, but if you want to do it yourself here are some tips:

1. Mow your lawn before aerating, and rake debris such as leaves, grass clippings, sticks, and other plant matter from the lawn.
2. Proper aeration requires moist soil, so irrigate heavily the day before, or aerate a day after it’s rained. You want the hollow tines, spikes, or blades to effectively penetrate the ground. However, be sure the soil’s not too wet or it will stick to the aeration tool instead of falling back easily to the lawn.
3. Mark any obstacles on your lawn, such as sprinkler heads, irrigation pipes, septic or utility lines, so you don’t damage them. 
4. For core aerating, use a tool or machine that removes plugs approximately 2-3 inches deep, 1/2 to 3/4 inches in diameter, and about 2-3 inches apart.
5. Work back and forth across your lawn, making several passes in different directions. Concentrate on known compacted areas.
6. Leave the plugs on the lawn. They’ll disappear when you mow, when it rains, or after you run the irrigation system a few times. You can also rake them into the lawn.
7. Fertilize and water the grass within 48 hours. Any overseeding should be done after aeration.

Please note, this article is for information purposes only.  South Austin Irrigation does not offer lawn aeration services.

You can rely on South Austin Irrigation to keep your irrigation system operating at its best.  Call the experts at (512) 534-7449 or fill out our online service request form for professional maintenance and repair to your sprinkler system.