Equipment Notebook: Aug. 2000, Aerators

More than 50 percent of North American lawns are at least 10 years old, according to Shayne Newman, president, Yard Apes, New Milford, Conn.

Due to their age, these lawns can benefit from aeration, which relieves soil compaction and thatch problems. This allows for better air, water and nutrient movement through the soil, resulting in healthier turf, Newman said.

This fact might create the illusion of instant dollar signs in a contractor’s eyes, according to Newman. But to successfully add aeration to a service mix, a contractor must understand the types of machines available and the proper way to use them.

AIR POCKETS. Aeration is the practice of creating small, evenly spaced 3-inch deep, ½-inch-wide holes in a lawn, getting air and nutrients into the roots and venting subsurface gases created by decomposing roots. The pulled soil plugs are dispersed to spread soil nutrients over the turf surface.

"Core aeration benefits a lawn by breaking through the dense thatch and speeding up its decomposition; opening up the soil to permit free movement of water, fertilizer and air; and relieving soil compaction and giving grass roots room to grow," Newman explained.

The best time for aeration service depends on the turfgrass type and location.

"In spring, aerate before applying preemergent herbicides," said Jim Schweigert, president, JRCO, Minneapolis, Minn. "In fall, aerate before late season fertilization. You can enhance root growth by aerating in conjunction with overseeding. Warm-season grasses are usually aerated in mid-spring to summer, but not until after first spring mowing, during green-up or when dormant."

With cool-season grasses, Bob Brophy, director of the lawn products division, Turfco Manufacturing, Minneapolis, Minn. said aeration is becoming primarily a fall practice. "If you aerate in the spring, the grass is already in its peak growing season, so by the time the soil is loosened up – which takes about two months – it’s past its prime growth point," he said. "If you aerate from September to December 1, the holes loosen all winter and then next spring the soil is ready for the turf’s prime growth. Plus, aerating in the fall keeps the crews busy during a down period and can extend a contractor’s season another 60 days."

TOOLS OF THE TRADE. There are a number of aerators that can loosen soil and break-up thatch. Walk-behind aerators come in two families: rolling or drum aerators, where the tines are fixed to a disk and roll into the ground, and reciprocating or piston aerators, with tines that move up and down at a quick speed making holes in the ground.

According to Brophy, rolling aerators have a key advantage over reciprocating aerators. "When rolling aerators hit obstacles, they bounce over them and don’t break because the tines are made out of heavier steel, which amounts to less machine downtime," he said. "Reciprocating aerators have tines that are tubes of steel instead of solid spikes. So they are made of thinner steel and are more susceptible to breaking. The maintenance on a reciprocating aerator will run 10 times more than on a rolling aerator."However, with rolling aerators, contractors can’t place as many holes per square foot in the turf as they can with reciprocating aerators; the lawn will need two or three passes with a rolling aerator," Brophy continued. "With a reciprocating aerator, only one pass is necessary."

"Some cons of rolling aerators include the fact that they cannot be maneuvered around obstacles without first lifting the tines up out of the ground," noted Rose Mary Becker, sales manager, Classen Manufacturing, Norfolk, Neb. "With reciprocating aerators, however, the unit continues to aerate while steering around corners and obstacles, thereby offering greater productivity."

Walk-behind rolling aerators are typically less expensive than reciprocating aerators, Brophy said, but Newman pointed out that cost shouldn’t be the only consideration when purchasing an aerator. "Contractors should look for durability above cost," he said. "Decide what machine you want based not on cost difference but on the one that is built better or will save you time. Any piece of equipment that can do the job in one-half or two-thirds the time is worth the cost."

Carla Herron, director of marketing and business development, BlueBird International, Denver, Colo., said looking for aerator durability and operator comfort means checking out specific areas of the machine. "Height adjustment controls give contractors flexibility," Herron said. "Removable weights can help simplify transport. Free-wheeling tines can help an operator maneuver in turns and in other tight areas, which can help increase productivity."

An aerator that accommodates both solid and hollow core tines is also beneficial, noted Peter Whurr, vice president of product management, Textron Golf & Turf, Racine, Wis. "Contractors should look for equipment that will stand up to the vibration and abuse demanded by the operation," he added.

GETTING ATTACHED. According to Newman, walk-behind aerators are simple to use, but can be labor intensive, especially on larger properties. In addition to his 21-inch walk-behind aerator, he uses an aerator attachment on the front of his mower to aerate a 48-inch wide path. "These attachments are great if you have a flat property without gates to get through," he said.

Aerator attachments, available for front or rear mount on a mower, operate off of the power of the mower, Schweigert said. "There are no other engines or belts for upkeep," he said. "Also, the attachment disconnects from the mower with two clevis pins, allowing the operator to proceed with mowing."

Aerator attachments on riding mowers also produce little operator fatigue, Becker added, pointing out that these attachments also have some cons. "They rely 100 percent on weight for adequate tine penetration, they are too wide to fit through gates and are not maneuverable in tight areas."

"Aerator attachments can also affect ease of maneuverability and the process of loading and unloading a trailer – they tend to take up more room," Herron added.

"Also, look for an attachment that aerates while turning," Schweigert said. "Because of the speed of the mower, we find most operators using the aerator will cross-aerate placing up to 12 holes per square foot."

OTHER TOOL BOX NEEDS. Besides an aerator or aerating attachment, some other tools may be necessary for contractors to start an aeration service.

Before aerating a lawn, contractors should use small flags to mark areas where underground obstructions, such as irrigation systems, low voltage lighting cables or invisible dog fences, are so that they don’t move aerator tines, which make 3-inch deep holes in the ground, over these areas and damage these objects. "Invisible dog fences and low voltage lighting cables are typically buried just 2 to 3 inches underground," Brophy explained. "Irrigation systems are supposed to be buried deeper - 6 to 12 inches deep – but that’s not always the case on every property. Contractors should ask to see the homeowner’s or property manager’s irrigation contract to double check the depth of they system and then mark these areas anyway to be cautious."

A vertical mower or dethatcher can be a good tool to have if the customer requests that the soil plugs be broken up, instead of left on the lawn to naturally decompose, Brophy added (See Breaking Up above).

Newman said a backpack blower or leaf rake can come in handy to clean off walkways after aerating. "Sometimes this is necessary when pulling the soil plugs stirs up some dirt," he explained.

Because an aerator’s job is to pull up soil plugs and move over turf, the machine gets dirty, Brophy said, which is why he recommends contractors obtain a power washer for proper cleaning of the machine.

SELLING AERATION AS A SERVICE. Contractors can sell and price their aeration services profitably by including them in an annual service contract, Herron pointed out. "This keeps customers using one company instead of going to someone who only offers aeration and not a total service package," Herron said.

Newman sells his aeration service with his mowing and fertilization service. "Of the lawns we mow, we were able to sell 60 to 70 percent of those customers an aeration and fertilization service," Newman enthused.

The charge for aeration service should be 2½ times the cost of mowing service, according to Brophy. "For example, near the Chicago area, contractors are getting $35 to mow a lawn and $100 to aerate it because of the additional benefits of aeration," he said.