Vertical mowing (
Verti-cutting) is a one of those maintenance practices people hear about but may not understand why it is done. As usual, explaining involves a little background info. I'll be pretty fast and loose (as usual) with the "facts" but generally most of what is written is accurate....the info can be more detailed but that has a tendency to translate into more boring.
Bentgrass has a creeping growth and on putting greens it spreads via stolons not seed. This type of growth can lead to "grain" which is a term used to describe a situation where the turf leaves are all laying in one direction (usually down hill or what ever way the water flows). Putting with the grain
exaggerates the roll and break. Putting against the grain has the opposite affect on ball roll (i.e. slower and less break). Generally, grain is more of problem at higher heights of cut (
HOC) since there is more leaf blade to lay over. However, at lower
HOC when we are trying to grow the greens with more emphasis on density and root growth we can sometimes create conditions which may lead to somewhat "grainy" turf. One method for controlling grain is vertical mowing. The cutting heads we use (3 heads in total) contain 36 tightly spaced carbide tipped blades with 10 teeth per
blade for a total of 108 blades (1080 teeth).
Blades on a single
verti-cut mowing head
Triplex mower with
Verti-cut reels operating
You can adjust the depth of the verti-cut heads to achieve desired results. For example, this spring we went about 1/2" deep on the weak greens to increase light and water penetration as well as to remove thatch and, hopefully, cut any existing bentgrass stolons which would then develop into shoots and help increase density. This time out we were more focused on grain control (i.e. standing up the turf that was laying over) and did not go as deep. Verti-cutting doesn't immediately speed up a green but may instead make for a bumpier and slower green. One way to address the bumpiness is to follow the verti-cut with a light sand top-dressing. The sand will level the grooves left by the verti-cut blades as well as protect any damaged turf from drying out.
Top Dressing Being Applied
If you played this past week you would have seen the linear lines left from the
verti-cut heads. Usually, with a light
verti-cutting the lines will grow out within a 6 or 7 days. Most
likely we will do one more later in the season but this time the emphasis will be more on thatch removal since controlling the thatch in greens is one way to lessen opportunities for overwintering diseases. The more astute of you will note that I reference
verti-cutting as it relates to
bentgrass not
Poa annua which is the turf species I claim inhabits all our greens.
Poa is more a upright, clump type growth which is less prone to grain. We have enough greens with a blend of both bent an
poa that
verti-cutting for grain control is necessary.
Perennial poa can spread laterally via stolon so
verti-cutting on old
poa greens may increase density by cutting stolons. Also, even at the higher height we
verti-cut this time out, we removed extra material that could contribute to thatch
development.
River Watch
August 18
This week saw the first time the river pumps (also called transfer pumps) shut down because of low water at the river intake. It took 2 guys most of a day to dig, expose, and clean out the area around the river intake with shovels and garden rakes. The end result was the ability to re-start both pumps inside the transfer station. The red paint mark on the rock on the right of the picture is there so we know how deep to dig to expose the conduit leading to the river intake (FYI conduit is 47" below the paint mark). This late in the year as the flow in the river decreases you can observe a visual difference daily versus weekly.
