Wednesday, May 6, 2009

Vertical mowing of greens

We've been trying to groom/vertical mow our greens on a regular basis. Yesterday, we did all 19 greens using our riding mower verticut units.

Vertical mowing has a number of benefits for our greens.

  1. Reduce thatch in the top layer of the green. Thatch is a combination of living and dying plant material which accumulates in the top mat layer of the green. Most greens should have approximately 1/2" of thatch(mat) which help protect the turf from injury and impact from golf balls.
  2. Incorporates sand into the thatch layer which helps with oxygen exchange and protects the crowns(growth center) of the plant. Oxygen allows the microbes to thrive in this layer which help in keeping the thatch layer broke down which allows for water penetration and the release of nutrients into the roots of the plant. Greens that have too much thatch have a tendency to feel spongy when you walk upon them and will ball mark rather severly.
  3. Bentgrass by its very nature will prefer to lay over to the side. Turf that is laid over will become long creating more surface area for the ball to roll upon which then creates drag on the golf ball. The old Johnny Miller phrase grain which speaks to the direction the turf tends to grow or lay over. In most cases in tournament golf, cutting heights are so low and tight that grain very rarely exists to any extent. We want the turf to stand up straight so it will be cut cleanly and consistently. Topdressing sand will be able to be worked around the upright grass blades which reduces fricton on the ball which increases speed.
  4. Bentgrass will also rejuvinate from the slicing action that the verticutter uses to do its work. There are over 2500 grass plants per square foot which can become very tightly compacted in time.

Below is a one inch plug which I took out of one of our greens this morning. The top or turf side is to the left and there is about an 1 1/2" of soil on the right which make up the base of our greens. Between the surface and the soil is a sand layer which varies from 3-5 inches from green to green at our facility. We have near 1" of thatch which is ok but needs to be controlled. Regular topdressing, aerification, vertical mowing and control of fertilization will help in keeping this material from expanding any further and will hopefully reduce the amount of thatch we have on our greens in the future.

The picture below shows the vertical mowing lines and how the turf is forced to stand tall.

Assistant Mike is using the vertical mower without baskets to incorporate the sand that is being pulled up back onto the green surface. As Nash had questioned the other day about going a different direction, we do try to alternate the direction from time to time which will assist in reducing the amount of grain in our greens. We also change our mowing direction daily to help in reducing grain in the turf.

Close up picture of the vertical mowing blades. The units are set to a depth below 0" so that it will cut into the surface of the turf. Each blade is seperated by about 5/8". As the unit moves forward on the green, the hydrallics of the system turn the unit which then allows it to cut into the surface of the green.

This is a view of the complete unit. It is the same size as our mowing units which can be placed on the same mower.

Assist Skip is putting a light topdressing on the green so it will help with smoothing our surfaces and allow the sand to move into the profile of the vertical mowing.

We then took our cocoa mat drag to our greens across the direction that we would mow which would stand the turf up further and they would be mowed with a normal mowing unit.

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