Throughout the Northeast, golf courses are shifting into winter maintenance mode now that temperatures have cooled down and most of the leaves have fallen. This break in the action is a great time to deep-tine aerate greens, a cultural practice that has many benefits but is often omitted from the agronomic program. Aerating deeply with solid tines requires no cleanup, is minimally disruptive to play and should be performed at least once annually. Traditional core aeration impacts a maximum depth of 4 to 5 inches and improves soil physical characteristics for better rooting and water infiltration in the upper rootzone. Yet over time, the layer below the frequently core-aerated portion of the rootzone can become more compact, slowing water infiltration and impeding root depth. Shallow rooting and excess moisture near the surface does not give turf a great growing environment to withstand the rigors of summer.
Penetrating this deeper layer is necessary for good turf health, but setting a deep-tine aerator to maximum depth when significant compaction is present can disrupt the surface. Instead, set the machine for 1 to 3 inches below the traditional shallow aeration depths to start. This penetrates the compacted layer while minimizing surface heaving. Another beneficial tactic to use when deep-tine aeration is performed for the first time in many years is to increase tine spacing. As more deep-tine aeration is performed, the profile deep in the rootzone loosens, allowing you to increase the maximum depth and reduce spacing without serious surface heaving. As tines are driven deeply into the profile they also tend to “kick” laterally, further fracturing the subsurface.
Deep-tining greens increases aeration porosity for improved water infiltration and gas exchange, creating a better growing environment. The deep-tine holes also don’t disrupt a surface like hollow tines and generally provide acceptable ball roll afterward. The turf is growing slowly at this time of year so aeration channels remain open for water to infiltrate the surface all winter long, reducing the risk of crown hydration injury. An additional benefit is when precipitation fills the channels, freeze-thaw cycles will further fracture the soil profile, increasing aeration porosity and encouraging deep, strong roots. Implementing a deep-tine aeration program will give you some peace of mind this winter and improve turf health next summer.
Northeast Region Agronomists
Darin Bevard, senior director, Championship Agronomy – dbevard@usga.org
Elliott L. Dowling, regional director, East Region – edowling@usga.org
Brian Gietka, agronomist – bgietka@usga.org
Information on the USGA’s Course Consulting Service