Growing a great green lawn can be a great big pain in the neck. From seeding to fertilizing to mowing, it seems like there’s and endless list of repetitive chores associated with maintaining a nice, verdant bed of grass. Well, lawn aeration is yet another chore that is often unduly overlooked — but a practice that may pay off in boosting the overall health of your lawn, thereby saving some labor headaches in the future.
The process of lawn aeration involves extracting cores of soil from the lawn area. It is a standard contractor technique for ground-maintenance professionals. In the context of landscape and lawn maintenance, aerate means “to supply with air.” This is accomplished with a device that has hollow teeth or tines. These machines are available in walk-behind models, or can be towed behind a tractor. As the machine’s drum spins, the blades or “pluggers” cut into or remove cores of soil. With core aerators, the extracted plugs of soil range from 1/4 to 3/4 inch in diameter and 2 to 4 inches in depth. The process of aeration serves a two-fold purpose: It helps control thatch development and reduces compaction on the surface of the soil.
Spike aerators cut into the soil with tines. “Plugger” aerators actually remove small cores of the topsoil.
Thatch and Compaction
Thatch is a layer of “woody” organic matter that develops between the soil surface and the actively growing vegetation. Development of thatch greater than 3/4 inch thick can lead to problems with lawn disease, insect infestation and drought. Aeration helps minimize thatch accumulation by removing some of this buildup. Additionally, the process increases the activity of microorganisms within the soil that decomposes the thatch layer. Aerating the lawn achieves a mixture of thatch and soil that retains more nutrients and water than a layer of pure thatch.
Signs of soil compaction include foot-worn areas, rapid browning in dry weather and slow drainage after rain. Because proper aeration fights soil compaction, many professionals favor the plug-type aerators over blade-type aerators. Blades or spikes that simply poke holes in the soil, rather than remove plugs, can sometimes add to the compaction of the soil. For this reason, spike or blade aerators are only recommended for moderately compacted soil.
Keep in mind that core lawn aeration should only be done to correct problems of soil compaction and thatch buildup, not as a routine part of lawn care. Aerate the lawn using an approach suited to the degree of compaction. Test the lawn’s level of compaction by spraying it down with a garden hose. If the water doesn’t soak in quickly, the soil is compacted. A general rule is that you should be able to press a wooden matchstick into the soil with ease.
Core aeration removes plugs of earth from the surface of the lawn.
This eases compaction by thinning the tightly packed soil while also removing built-up thatch.
The process allows water and nutrients to enter the soil and nourish the lawn.
The Right Equipment
For those with small yards or gardens that suffer little compaction, systematically pricking holes with a garden fork or other hand- or foot-operated aeration implement might suffice. But for larger yards, the smart move would be to rent a gas-powered lawn-aerating machine from the local equipment-rental outlet. Price varies, but renting an aerator typically costs around $70 per day. If you’re not a lawncare professional, buying the right equipment can be costly and will take up valuable storage space for equipment that won’t get regular use. You may even find it cheaper to hire someone with the right equipment to do the job for you.
If you decide to rent or buy the equipment, select a machine that is powerful enough to get through the heavy, compacted soils, removing plugs several inches long.
And before using the aerating machine, cut the grass short. Then run the machine over the lawn. With core aerators, the machine will leave the plugs of soil on the yard. The just-aerated surface strewn with soil plugs isn’t a very attractive moment for the lawn, but leave the plugs in place because they will return nutrients to the soil as they dissolve back into the lawn. Using a lawnmower to break up the plugs will help them to dissolve. As the grass grows, the plugs will be less noticeable.
It should be noted that spike aeration can be done annually, but core-type aeration should only be done once every three years. Also, aerating a lawn is generally easier to do when the soil is moist. And although the job can be done any time of the year when the ground isn’t frozen, lawn aeration is typically done in the autumn or in the early spring prior to fertilizing.