Course Maintenance Schedule / Greens Aerification
Over the next few paragraphs we will go into detail about why it is necessary to aerify and why we pick specific times of the year to complete these processes. We will use the DuPont course maintenance schedule as an example. The DuPont Course Greens are a blend of Penn A/1 and Penn A/4 bentgrass which are a superior cultivars used for putting greens because of their very dense upright growth pattern, ability to withstand very low mowing heights, and disease resistance qualities. Because of their aggressive growth pattern these cultivars develop thatch more quickly than the older variety of bentgrasses. Thatch is the layer of organic matter between the surface and the root zone comprised of dead and living stems, leaves and roots. A small layer of thatch is acceptable, however an excess layer of thatch leads to soft spongy greens that hold water near the surface affecting playability. Excessive thatch also negatively impacts the exchange of oxygen and water from the atmosphere to the root zone and creates a breeding ground for disease. The single most important factor in maintaining healthy turf is to build a strong deep root zone so that the greens can hold up to the physical and environmental stress from the summer months ahead. In order to build a strong root zone the roots must have access to oxygen and water at all times. A dedicated cultural maintenance program is necessary to keep thatch at minimal levels.
We use a variety of methods of aerification on the DuPont, Nemours, and Montchanin Greens. Typically weather permitting in March we schedule Dryject aerification before the golf season begins. Dryjecting involves using a machine to inject sand thru the thatch layer into the root zone by using high pressure air and water. This process is completed with minimal surface disruption as the greens are playable the next day. This procedure firms up the greens from the late winter thaw that leaves the greens very soft. The holes on the surface grow over as the bentgrass becomes more active, but the channels created beneath the surface remain open for the entire season allowing the exchange of air and water. Core aeration is scheduled for the first week of June. This process involves removing a core of thatch with a small diameter (1/2”) hollow tine. The void is then backfilled with sand so that air and water can be exchanged. Core aeration is scheduled at this time because the bentgrass is aggressively growing which allows for a much faster recovery time. When the weather is favorable the greens typically heal over in about 7-10 days. Often times when this procedure is performed in early spring recovery time could last a few weeks because the greens are not as active. This aerification is probably the most critical because it will build new strong roots that help the greens survive the physical and environmental stresses of the tough summer months ahead. The type of aerification performed in August usually depends on the overall health of the greens and the weather forecast at that time. Over the last couple of years on the Dupont Course we have punched a hole with a solid tine to provide relief to the roots and aid in recovery of the stress from the summer months. This process is also known as venting. A core is not removed and the greens are playable the same day. If the weather allows we will apply a light sand topdressing as well. Another (1/2”) diameter hollow core aeration is performed in October. This is the time of year when the roots are most actively growing and it is important to build the root mass for winter dormancy and spring green up the following year. In between aerification dates when the weather allows we will verticut and apply light topdressings which aids in ball roll and playability while diluting the thatch layer.