From Merriam-Webster Online Dictionary:

Main Entry: aer·ate
Pronunciation: ‘a(-&)r-”At, ‘e(-&)r-
Function: transitive verb
Inflected Form(s): aer·at·ed; aer·at·ing
Date: 1794
1 : to supply (the blood) with oxygen by respiration
2 : to supply or impregnate (as the soil or a liquid) with air
3 a British : CARBONATE 2 b : to make light or sparkling
- aer·a·tion /”a(-&)r-’A-sh&n, “e(-&)r-/ noun

Aerate, in the context of landscape and grounds maintenance, means “to supply the soil with air”. It is a contractor technique to aid in maintaining and improving lawns. Aeration improves the lawn appearance, usability, and it’s ability to absorb water from irrigation. Aeration is important for the garden as well as the lawn, but the techniques for garden aeration are different than for lawns, and the subject for another column.

An aerator is the equipment that performs the work and it’s a machine every gardener and landscape maintenance contractor should own. If you perform lawn maintenance or renovate lawns you need an aerator. Aeration is a standard component of any grounds maintenance program. For seasonal work you can rent the equipment. If you have a larger customer base you should consider adding an aerator to your contractor equipment. Landscape companies will generally find it more profitable to own the equipment instead of renting.

First let’s discuss the need for aeration and the benefits of a regular aeration program in landscape maintenance.

Grass roots need air as well as water and fertilizer. The grass can actually poison itself as a result of the various chemical processes that occur in the individual grass plants if the grass roots do not have enough air. Soil that lacks sufficient air can result in; slow growth in the affected grass, excess irrigation runoff due to poor permeability, shallow root systems, and a lawn that’s highly susceptible to insects, disease, and heat damage.

Soil compaction is the most common example of soil deficient in air. The growth habits of grass in compacted soil are shallow root development, a substantial decrease in the number of grass plants per square foot, and an inability to properly use applied fertilizers.

Soil compaction in lawns is caused primarily by pedestrian traffic, whether it is children playing in a playground or people taking shortcuts across a lawn. Stopping the use of the affected lawns is generally impractical. A better solution would be frequent aeration and, depending upon the composition of the soil, the application of lawn and garden amendments such as peat, sand, or gypsum.

The benefits of aeration are an increase in the:

  • growth rate of the grass thus an improvement in its ability to withstand and recover from pedestrian use
  • ability of water and fertilizer to penetrate to the grass roots
  • soil’s absorption rate from irrigation
  • root growth activity contributing to the strength and health of the grass
  • ability of bacteria present in the soil to break down and decompose the thatch layer thus increasing the soils ability to hold sufficient amounts of moisture between waterings
  • grass’s ability to withstand low water situations and heat stress

Aeration is a technique best applied in late summer or early fall for cool season grasses and in the spring for warm season grasses. This can also be a good time to overseed and topdress/amend the aerated lawn. One drawback to aeration is that it increases the probability of weed infestation thus it can become important to include pre-emergent and post-emergent weed control measures. In addition to being beneficial to the lawn, these services are an add-on profit center for the landscape maintenance contractor. Aeration services are also often offered by garden centers and nursery businesses.

If you have a severely damaged lawn or a lawn area that undergoes heavy and frequent use you might consider aerating these areas several times throughout the year. Remember, aeration does damage the grass, so aerate “lightly” by using a slightly wider tine spacing or only one pass.

An aerator that pulls plugs is more effective than one that simply pokes holes. An aerator that pokes holes can further compact the soil. Soil compaction decrease the available air to the grass roots and causes excess irrigation run off. Either remove the plugs or break them up (use a mulching lawn mower or close the catcher chute on a standard mower). Always apply any amendment immediately to achieve maximum penetration of the amendments into the soil. The holes have a tendency to collapse especially if pedestrian traffic is difficult to keep off.

Contractor equipment varies from dedicated aerators that pull plugs to rototiller add-ons that simply poke holes. As discussed, pulling plugs is better. You will also find the dedicated aerator to be easier and more efficient to use.

Aeration is also a way for many landscape maintenance contractors, gardeners, and garden centers to make more money. Most offer the service to their customers as an additional service. Pricing and costs will vary. Some charge by the square foot, others by the job. The average price in Southern California is about $45.00 per 1,000 square feet for owner occupied single family residences. Other large landscape maintenance contractors offer aeration as part of the contracted service, especially for large residential communities where the single billing cost for aeration could be prohibitive. They calculate the cost of aerating and divide the result by the term of the contract (usually one year, 12 months) thus charging the customer a portion (1/12th) of the total cost each month. This makes the service affordable to the homeowner association or property management company and brings in more money to the contractor. The same technique could also be used by smaller lawn maintenance and gardening companies.

Aeration should be part of your grounds maintenance and irrigation service. Its an inexpensive way to improve your customers lawns and make more money. It also makes it easier to get those yearly increases in fees and keep customers longer. Happy customers pay much better than dissatisfied customers. Aerating really can make a big difference in the appearance of your customer’s lawns! Competition in the Green Industry is strong and added services like aeration will help to put you out in front of your competitors.