Quality of Core®

Quality is at the core of what we do. At Classen, we know achieving the best Quality of Core® for core aeration comes down to three factors: core pattern, core quantity and core depth.


The number of tines, tine spacing, rate of operation and the tine drive mechanism determine core quantity. Tine drive mechanisms include tine wheels or tine rods.
Tine wheels are circular disks spaced along a rod or shaft with numerous core tines mounted and fanned out around the wheel. The number of tine wheels, number of tines mounted per wheel, and their distance to one another along both the shaft and the tine wheel determine the number of cores the unit is capable of pulling per swath. The tines are fixed and spaced to produce a consistent pattern regardless of the speed of operation.

Tine rods are mechanically or hydraulically driven in and out of the ground. The quantity of cores pulled per swath depends on the number of tine rods, their rate of reciprocation, and the speed in which the unit is being propelled. The distance between tine rods along the shaft is fixed. So, if the unit has four tine rods set six inches apart along the shaft, the operator will need to make multiple passes to achieve the proper core pattern to effectively relieve soil compaction.

Core Depth

Proper core depth is vital in alleviating soil compaction. Professionals surveyed suggest achieving a depth of two to three inches is needed to sufficiently relieve most soil compaction conditions and give the root system new room to grow.

Accounting for an average half-inch thatch layer, you will need to aerate at a depth of at least two inches to relieve soil compaction. And you should allow an additional half-inch or so to create a growth pocket to promote existing root growth.

Depth consistency is an important factor in proper turf aeration. It is important to utilize an aerator that allows you to set a maintained depth or at least to lock in a maximum depth setting.

Inconsistent core depth can be a problem with aerators that maintain tine depth hydraulically. Stand-on aerators for example, utilize hydraulic pressure to drive and maintain tine depth. However, hydraulic pressure can vary and there is no way of knowing from the pressure gauge exactly how deep or shallow the tines are penetrating the soil at any given time. The Classen Stand-Aer® features tine depth-stop settings that maintain a maximum depth in a variety of settings for flexibility.

Regardless of the unit you choose to use: walk-behind, stand-on or tow-behind; core depth is something you’ll want to monitor. Make a first row pass and pick up a few cores to make sure you are achieving the depth needed and that you are maintaining consistent depth.

Core Pattern

Core pattern is considered by many professionals to be the most important factor in determining Quality of Core®. The proximity of tines to one another determines core pattern. This includes the distance between the tine rods or wheels along the shaft and the distance from one tine tip to the next along the wheel or the distance traveled before the tine rod completes a full rotation piercing the ground again.

Turf care professionals recommend a core pattern distance of 2-3-inches between cores. As such, core pattern should be a primary consideration in choosing a core aerator.

The denser the tine placement of the unit, the tighter the core pattern it produces. The result is a more effective treatment for the turf and higher productivity for the operator through fewer passes required to achieve the recommended core pattern.